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Old 9th June 2014, 10:35   #16
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

Planning to take off for Ladakh Wednesday, but only 200km locally done, too early for the first service - and it would be too late by the time I got back. So what to do? ROAD TRIP!

The traffic northwards (towards Rohtang) is pretty horrible these days, and I'd be heading that way soon anyway; and Dharamsala seemed a bit far - so what to do?

Then the idea struck me: Billing. Kangra Valley and the lower foothills are rather hot, dry and parched right now compared to our Upper Kullu Valley, which is green and well-watered. But Billing - that ideal paragliding jump-off point above Bir - looks over it from its perch at a cool and lofty 2400m - same as our upper valley village! Been there (and beyond, to Rajgunda, before the road was opened) on the KB125, but the place was always abandoned. This time was different:

(One of the narrowest bridges over the Beas, near Bhuntar)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05075.jpg

(the road ascending through forest)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05079crop.jpg

(up top, with the "birds")
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05099crop.jpg

(only two (easy) ways back down)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05172.jpg



Will add a little tech section here (thought I should get this up ASAP for the sake of others planning for hill travel this season):

Lots of complaints about the Impulse's lack of power in the hills, right?

Besides the lack of displacement (150cc), here's why:

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As mentioned somewhere earlier, this thing's got a #132 main jet (the jet on the right) in the Keihin carb. Huge. The Hero showroom mechanic, whose done about 1,100km on his Impulse, said his bike's engine, like mine, was missing at the altitude of Solang (just a bit above us). Sparkplug absolutely black (should show light brown, ideally). So the bikes' stock jetting is causing them to miss at 7,500ft. Just imagine how badly it would run (if it would run at all) at 13,000 - or 18,000ft!!! These engines are so smooth and so muffled that some people probably didn't even realize they were missing - they just thought there was "no power".


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The usual solution (above): Have a roadside mechanic put a loop of wire through it. As I mentioned in another thread, I don't like this at all. Too hard to know how much fuel you're actually getting and whether it's right for your bike. Even if it were right, it's too hard to consistently repeat in the future (varying wire sizes, shapes of the loop, position in orifice, etc), and moreover, it might allow some small quantity of fuel to leak past the threads, as the jet is cannot now be fully seated. Bad Jugad.

For my bike, I took that wired jet (actually out of a Fiero), which was a much smaller number, removed the wire, and drilled out the orifice with a #118 (1.18mm) drill. So now I've got a #118 jet to replace the #132 and the missing is totally gone, and the plug color looks perfect . I will eventually do some more fine-tuning, but this isn't too far off. It ran fine even down at lower altitudes (i.e., Mandi / Jogindernagar - 3,000ft, etc) though it would probably be too small for the plains and cause surging and worse, overheating.

Interestingly, on the basis of complaints, the Hero dealer (Kullu) had actually experimented a bit and found that the jet from an Achiever (which must have a smaller carb than the Impulse's 28mm venturi Keihin) worked well. And guess what the Achiever jet size is... #118!!! I got lucky there - it was the only drill bit I had in that range.

Hero might not stock these jets, but you can get them from at least 2-3 suppliers I know of in Karol Bagh, Delhi, and most likely in other metros / towns (this showroom had to order from the market, too, since Hero didn't send them when ordered).


RE: Impulse riding impressions, after 400+km in a day...

Power output is fine, so long as you aren't afraid to rev it. Felt every bit as good as the 2012 CBZ I rode last year. 4,000-up is smooth, and it pulls harder from 5,000-8,000 (being fresh, I kept it to 5-6,000rpm max - if I could avail of the 8,000rpm limit, even better performance could be realized, especially for the 1-2 shift, where the biggest gap in ratios exists).

Anyway, I felt I could ride as fast as I wanted to almost all the time, excepting on the steepest / longest of grades, where I really didn't want to push the new engine too hard.

On road handling is really very good, in terms of turning and control. Stock tyres, as expected, seem pretty heavily road-biased, and while better than typical OE tyres off-road, still not much use there. Dunlop Monster Trail is looking pretty aggressive for that purpose.

I like sitting up high, for purposes of visibility. Ran into an unbelievable amount of tourist traffic on the way back home. Must've overtaken literally hundreds of cars, and found the seating position helpful towards doing that in relative safety.

Brakes are fine.

I wish the suspension were set up a little softer for rough, broken roads. Pretty sick that every other mono-shock bike in India has an adjustable unit, and this bike, which needs it most, doesn't. It really almost feels like more of an offroad setup, and I'd guess something like a Unicorn (or even the latest RE's) would've been more comfy (especially with its wider seat) for normal road use. Not unusual to have my bum bouncing off the seat here. If one wanted to ride really fast over really broken terrain, this level of stiffness would help soak it up, so it depends on your riding style, I guess. Just sayin'... after 400km - and much of that on relatively smooth roads, my bum is definitely feelin' it. I don't know how its going to fare for Ladakh.

Really missing the kill switch, which I've always been in the habit of using, and which makes quick stops for photos, etc, a lot easier. Going to have to install one (FZ?).

Gearing, as everyone says, feels a bit odd on the 1-2 upshift - but surprisingly, if the manual is correct, the gearbox ratios are identical to those of the Extreme. Going to check and see what the Unicorn has. There's a noticeable "clunk" on the 1-2 shift, partly because there's no rubber drive cushion in the rear hub like most Indian bikes have, and partly due to the big ratio gap, which makes the drive cogs clash a little more as they mesh and match speeds.

42kmph on the first check (reserve to reserve), on a 200km engine and being pretty careless with the throttle;
45kmph on the second check, driving briskly but more conscientiously. Not bad for rapid hill highway travel. Pretty sure I could get close to 50 if I kept it conservatively steady & slow. BTW, the Hero tech says he's only getting 40 - he's still got the #132 jet... just to show how much difference it can make.

It took me about a half-hour to fabricate an adjustable "trail stand" to lift either the front or rear wheel for tyre changes, chain adjustments, etc. Will post a few photos when I get the chance.

(The Impulse: Good. Gets you there. But not quite the same thrill)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05103cr.jpg

Regards,
Eric

Last edited by ringoism : 9th June 2014 at 11:01.
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Old 9th June 2014, 12:01   #17
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Default simple tyre changes for Impulse (home-grown trail stand):

Sure am glad I didn't turn down this bike only because it didn't have a ground-clearance-robbing (though convenient) center stand:

THE HOME-GROWN TELESCOPING TRAIL STAND:


(please don't have Chaachu bring an expensive factory-made one of these from North America):

I am not the first to do this, but maybe the first to post photos.

So here it is: 20 minutes labor, made from three pieces of simple steel tubing, 1", 3/4", and 1/2" respectively, utilizing a common 1/4" bolt & nut to hold whichever adjustment. 25cm long when collapsed, so fits easily in my tank bag or other luggage. Weighs maybe 300g. Simple markings with a permanent marker make the respective front/rear length adjustments easily repeatable:

(each of these long pieces around 30cm long)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05314.jpg

assembled stand
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05315.jpg

Front wheel: extended to about 45cm, support via the front leg guard.
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05317.jpg

Rear wheel: extended to about 40cm, support via the frame's engine cradle.
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05319.jpg

The universal rule: KISS (Keep It Simple, Stupid). And this, IMO, is simpler and less time-consuming than trying locate - and prop your bike up on - big stones (and probably a lot more stable, too). And less damaging than, in desperation, just laying the bike on its side.

Hope other Impulse owners / riders will find this helpful.

-Eric

Last edited by ringoism : 9th June 2014 at 12:13.
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Old 12th June 2014, 09:54   #18
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

Never going to get a bigger engine Impulse. Low cost off rode bikes need volumes to be viable. Not achievable because of the greater seat height. Even given the suitability of the Impulse for our "off road" condition roads! The CRF 250L never took off in Thailand because the average Thai is 5ft3in.

High end off road bikes will face the same obstacle : low volumes because of excessive seat heights AND high cost. High end "poser" bikes have a more universal appeal, reflected in viable sales figures.
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Old 14th June 2014, 16:29   #19
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

What a wonderful article to read. Straight from the heart. Had emotional, technical and spectacular aura about it. Beautiful. Makes me feel if I too should be going for an Impulse now.
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Old 15th June 2014, 11:01   #20
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Default Re: simple tyre changes for Impulse (home-grown trail stand):

Quote:
Originally Posted by ringoism View Post
THE HOME-GROWN TELESCOPING TRAIL STAND:

(please don't have Chaachu bring an expensive factory-made one of these from North America):

I am not the first to do this, but maybe the first to post photos.

Hope other Impulse owners / riders will find this helpful.

-Eric
Eric, not only impulse owners, but a lot of bikers will find this an excellent solution. I think for this alone this thread deserves a 5* rating.

Beautifullly written posts and the Techi info in layman's language is really helpful to many.

Please keep it up

Best regards & Ride Safe

Ram
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Old 18th June 2014, 16:40   #21
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Default How to run-in an Impulse

Q: How can one run-in a two-week-old, fully stock Hero Impulse?
A: Ride the Manali-Leh road up and back.


Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05450.jpg


Impressions / experiences?

The numerous complaints about the lack of power these bikes have for mountain riding are fully justified, assuming that the bike being ridden is completely unaltered from factory spec.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05613.jpg


Unfortunately Hero must have never tested these bikes at anything but near sea-level, and thus missed their opportunity to sort out either the carb settings or perhaps overly-restrictive intake/exhaust systems (the airbox /catalytic-convertor-equipped pipe come to mind) that would be required to make it a viable mountain-tamer. It was pretty sad to meet people along the way riding similarly powered / weighted FZ's and Unicorns and even 100/125cc Discover, etc, and having no serious trouble moving up over the passes, while this presumably purpose-built rough-road warrior in stock form would barely make it up the easiest of them (i.e., Rohtang).

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05344r.jpg


As per a previous post, I'd already changed the main (high-speed) jet from the stock 132.5 to a 118 - so though power started dropping off at part-throttle at altitudes above Mardi (11,000ft?), I at least had good running / power when the throttle was fully opened. As supporting evidence of adequate power levels, I'll say I was able to fly across the lofty More Plains at a solid 85-90kmph (till I hit a strong headwind), and at 50-60kmph uphill at around 17,000ft approaching Thanglang La top (this was with full luggage and a 75kg rider).

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05345r.jpg


So strictly speaking, there is no basic lack of power there.
It is possible to ride this bike pretty much as fast as conditions allow most of the time. I don't think I was ever overtaken by another bike while traveling uphill; I was doing all the overtaking out there, and running mostly well ahead of the unladen CL350 that was along with us. So it became plain to me that the low power problem is primarily in the tuning. With WOT (wide open throttle) operation, when I got into the right "groove" (combination) of selected gear, throttle position, rpm, and ground speed, power was just great. But the bike was still badly loading up (running rich enough to cause misfire) in the midrange, i.e., part throttle. I rode successfully all the way to Leh, but at any of the higher altitudes, it required a great deal of thrashing / deliberate clutch slipping / sustained high-rpm screaming to keep it moving at a good speed. I knew what needed to be done in the carb, but was hesitating for lack of experience / spare parts and certain unknowns with this particular (Keihin) carb.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05505.jpg


We spent a mere day in Leh (my companions were mostly interested in riding the passes, and I'd done Nubra / Pangong / Zanskar / Tso Moriri earlier), then headed back towards Manali. By the time we reached Pang, I just couldn't take it any more. I was actually being forced to ride in a risky manner, flying over very rough and slippery patches at Thanglang La as fast as possible just to maintain uphill momentum.

I really needed to resolve this - to open up the carb right then and there and lower the tapered main needle. Now on most carbs this is an easy task; after removing the throttle slide, the needle can be taken out, and it's retaining C-clip moved to a higher or lower groove to adjust midrange fuel flow leaner or richer, respectively.

(The needle, with slide, diaphragm, and retainer)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05846.jpg


But unfortunattely, when I took the needle out of the Hero at Pang, I was dismayed to discover that there are no grooves in it at all, just a solid flange at the top that holds it at its fixed height in the slide.

(The usual slotted/clipped adjustable needle at left vs. the Impulse's useless, unadjustable fixed flange unit).
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05850.jpg


If I'd wanted MORE fuel flow (richer), I could have simply slid a small flat washer or other spacer over the needle, to sit between its flange and the throttle slide to RAISE it. But unfortunately in this case, I needed LESS flow to compensate for the lack of oxygen at altitude - i.e., to go leaner - to LOWER the needle in relation to the slide - which for lack of any provision for adjustment, is impossible to do, apart from modifying either the slide or the needle itself.

If I'd been at home, I might've spent a little more time reviewing my options - but on the roadside, there was only one thing to do - and that was to take my little flat diamond-file and reduce the thickness of the needle's retaining flange by about 1/3rd. This would drop the needle, lean my mixture, and help eliminate the severely over-rich running I'd been experiencing.

(This is how I'd have done it if I was at home - needle chucked up in a spinning drill and worked with a flat file. Final flange thickness in my case was 1.20mm, but probably 1mm would work better at the higher passes).
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05852.jpg


If I needed to raise the needle to richen the mixture for lower altitudes again, it would be simple enough to add a washer to raise it back to its original height.

(a 1mm flat washer corresponds to the typical 1mm increments on a traditionally slotted needle).

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05853.jpg

Happy to say, IT WORKED!!! The bike would now normally pull up near the tops of the passes at as little as 3,500rpm. I gained 7kmpl on the return journey besides, now that the machine didn't have to be screaming / full-throttle all the time. Better yet, the bike still runs brilliantly here at a mere 2100m in Manali, and being that fuel flow has been decreased, I should be seeing even better mileage figures than the 45/L I obtained earlier (that with only the smaller main jet).

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05432.jpg


On this whirlwind tour (six days total including stay in Leh), I saw on the road probably half a dozen FZ's and the same number of Avengers; around four Unicorns, a couple Karizma's, a couple of Disco's and an old-model CBZ - with the balance of the hundreds of two-wheelers being the ubiquitous Bullets.

(Gotta admit, the RE looks simply timeless and oh-so-appealing up there....)
Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05523.jpg


I didn't see a single other Impulse anywhere, apart from the Leh-based local rental units sitting parked (the spare parts wallah there - who didn't stock any smaller carb jets - told me, "they have a pulling problem" [small wonder]). None until, that is, I was nearer home, moving up the back side of Rohtang. My carb slide had stuck closed (bad fuel???) and I was on the side of the road getting it freed up when the South-Indian owner of a black Impulse came along from the opposite direction and stopped. "It's not pulling" he said. He was thinking he'd made a mistake buying this bike - the same way I'd felt at points earlier along the way. "I can help you with that," I said. I had an extra #120 jet, which he trustingly allowed me to install - about a five-minute job. He took it for a little test run and said it had made a big improvement. I told him about the needle and showed him what needed to be done, but didn't want to mess with it on his bike, being a somewhat time-consuming, irreversible and not wholly refined procedure... but with the main jet, anyway, I knew he'd be able to get to Leh and beyond.

Other notes:

The suspension, even with the luggage, was still harder than it needs to be - but according to one pillion, is was much more comfy than the CL350 on rough roads. Moreover, I could pretty much run at any speed on any terrain with good control, never bottoming out the suspension.

The substantial ground clearance is also a boon. Very practical case in point:

We were stuck for 12-13hrs. atop Baralacha-La on the return trip, due to the snow being only cleared in one lane, and no enlightened officialdom on either end restricting the flow of big tankers and other lorries from both sides simultaneously. There were probably 70+ bikes up there, just as jammed as everyone else, but trying their best to get as close to the front of the mess as possible. We saw all that effort as pretty unpromising, so stayed put and relaxed further back in the line. So when a lane finally opened right around sunset, we were pretty much at the very tail end of a string of dozens and dozens of bikes that took off down the mountain in the dark.

Now first, the Impulse's reasonably grippy tyres and capable suspension allowed me, via the road's unpaved shoulders, to overtake (and not at all rashly) quite a number of these other bikes within the first few km. But I finally got ahead of them all - never to be seen again - when we suddenly came across a newly formed (via rapid snow-melt those past couple warm days) and dauntingly massive water crossing on that dark and moonless night. A pack of Bullets was stopped in front of me, their riders looking a bit unsettled and uncertain, looking around and wondering what to do. One or two of them were wading out into the waters to try and determine the best course, being that the current was strong, there were large stones beneath it, and a large drop-off midstream. Only a single Thunderbird had made it through thus far, and had stopped on the other side, its rider looking very wet and perhaps a bit harrowed. On the Impulse, I just wasn't concerned at all. Without hesitation, I swung around them all to the right and gunned it, launching into the torrential deeps and emerging moments later on the other side - never having to put a foot down or slip the clutch or push with my legs - all rather easy and undramatic from my perspective. It was a challenge, of course, but one easy to meet on such a machine. There would be three more night crossings after that, but none which presented any serious difficulty or cause for delay. Which is why of all those dozens of bikes, I was the first down the mountain to the checkpost at Darcha, and, many kilometers ahead of the pack, the first onwards to Jispa, where at around 10PM I managed to snag us the very last available room and treat myself to the one nice hotel with a very much appreciated hot bath.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05743.jpg


Re: the Manali-Leh road. I'd been thinking these past couple years that with the huge proliferation of tourists on the route, the explosion of tent camps, the thousands of bikers, the improving road surfaces - that the whole thing had become pretty well overrun and unappealing, a rather sterile and perhaps overly routine and "safe" experience. It had been four years since I'd been out there (having been over the stretch four times previously), and I wasn't really very inclined towards doing it again. But in retrospect I have to say, it still has the beautiful scenery and all the stuff of motorcycling adventure, if only for the road surfaces themselves: you've got it all here - pristinely smooth, sweeping blacktop; rocks; loose sand and dirt; gravel stretches; large heaves on long straights; ice; snow; running water; swift, deep crossings; mud; dirt; every imaginable type of turn; steep grades; and pretty well whatever else can be found on a road in this world. It's all good fun, the stuff of solid memories. And it is still dangerous, the end of many a machine and a few strong men besides - and deserves a measure of preparation, respect and caution.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05645.jpg


"All's well that ends well" seems the appropriate adage here. The Impulse experience started badly, right from the showroom (rusting bike with loose, knocking forks and multiple other issues overlooked in the pre-delivery inspection), to the first service (where the technicians failed to perform several important items very clearly specified in the checklist, and told me, in the very critical case of the oil filter/strainer that 'they don't do that'; and moreover in carelessness badly scratched the shiny red paint of the week-old bike's cowl in his attempt to tighten the steering head bearings, a job I could've done better myself), to the awful misfiring and power loss at altitudes fall short of lowly Rohtang, to the unexpectedly hard suspension damping and pathetic mileage figure of only 30kmpl in the high ranges... Yeah, it started out bad. Real bad.

But a little patience and experience, a little trial and error, the machine is getting sorted out - and I'm becoming confident that it'll ultimately be a great little rough-track and Himalayan tourer.

If you're looking for a turn-key touring solution, do look elsewhere. But if you don't mind engaging in a bit of persistent, hands-on fiddling, I think it's possible to arrive at a machine better suited than any other currently available in India to the sorts of roads and conditions that we adventure tourists frequent.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05458.jpg


Lastly, there is a human analogy here that comes to mind when I consider a bike like the Impulse: Like this machine, none of us is born perfect. We all have flaws and failings that tend to make life considerably less satisfying than it ought to be; It would be possible at points to think there's really no hope, that it was all a mistake, that a life is hardly worth persevering in. But then... with some openness of heart and mind, there is, in fact, the possibility of real, actual redemption - and "Life more abundant". It cannot be found in a bike; but having possessed it, it makes biking that much more satisfying.

Replacing the KB-RTZ offroad specials - My Hero Impulse-dsc05818.jpg


Regards,
-Eric

Last edited by ringoism : 18th June 2014 at 17:04.
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Old 18th June 2014, 18:47   #22
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Default Re: How to run-in an Impulse

Quote:
Originally Posted by ringoism View Post
Lastly, there is a human analogy here that comes to mind when I consider a bike like the Impulse: Like this machine, none of us is born perfect. We all have flaws and failings that tend to make life considerably less satisfying than it ought to be; It would be possible at points to think there's really no hope, that it was all a mistake, that a life is hardly worth persevering in. But then... with some openness of heart and mind, there is, in fact, the possibility of real, actual redemption - and "Life more abundant". It cannot be found in a bike; but having possessed it, it makes biking that much more satisfying.
This has easily taken over as my favourite thread from yours from the Marshal one. I think you have sealed the deal for me. If I do ever take up on the temptation to get back to riding, I will pick one of these up. It should do even better on Losar to Gramphoo late or early in the season.

The quote above is something that every fan of the wilderness and desolation in the trans Himalayas will identify with.

Got back from another string of days spent in your backyard, but didn't venture in the direction of Goshal. Was too hot to bike and remembered that you'd be out riding. We'll catch up for sure next time, which won't be too far off.
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Old 18th June 2014, 20:00   #23
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

Apparently, weight is the main factor to consider when choosing a machine for adventure motorcycling, both personal weight as well as bike weight. A 60 kilo rider would be happy with a 225 Serow, whilst a bigger person would need at least a DRZ 400s.

Bikes are prone to falling and one obviously needs to choose something one can pick up by oneself, so ruling out a 1150GS Adventure.

Leading to my question. Having used a proper off roader like a dr350, with a powerful engine and magnesium alloy suspension and rims, how do you find the Impulse? Is it a millstone around the neck in comparison? And is the ride too much of a buzz on highway stretches?

I just watched the Ultimate Biker Challenge, with this week's episode featuring the taking on of the Erzberg Rodeo, the hardest race in the world, with a KTM Extreme 300.

ttp://

It seems like the Impulse is too far from the right tool for the job. The Brazilian review showed the bike being used by farmers to carry chickens to the market, across mud roads, streams, jungle track and other assorted farmland!

Last edited by proton : 18th June 2014 at 20:16.
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Old 18th June 2014, 22:39   #24
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Default Re: How to run-in an Impulse

Thanks Eric,

Your post has answered so many questions about carb tuning that I have been looking for answers for a long time now. I have a almost new three year old Karizma guess you have motivated me to start working on it and make it touring capable. Any specific changes you would recommend for the carbed karizma ?
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Old 19th June 2014, 10:11   #25
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Default Re: How to run-in an Impulse

Quote:
Originally Posted by codelust View Post
It should do even better on Losar to Gramphoo late or early in the season.
That'll probably be my next ride, out to Chandra-Tal, in the next month or so. I love that stretch from Gramphoo to Batal especially - full of challenging water crossings, it truly separates the men from the boys .

Quote:
Originally Posted by proton View Post
A 60 kilo rider would be happy with a 225 Serow, whilst a bigger person would need at least a DRZ 400s.

Leading to my question. Having used a proper off roader like a dr350, with a powerful engine and magnesium alloy suspension and rims, how do you find the Impulse? Is it a millstone around the neck in comparison? And is the ride too much of a buzz on highway stretches?

It seems like the Impulse is too far from the right tool for the job. The Brazilian review showed the bike being used by farmers to carry chickens to the market, across mud roads, streams, jungle track and other assorted farmland!
I'd commented in an other Tbhp Impulse thread, before I bought mine, that the Impulse, at 13+bhp and 134kg, was going to be hard to accept vs. the DR's 30bhp and maybe 115kg...

But here's the reality: I've ridden everything from 50cc mopeds to an ST-5 Ducati (tourer with the 916 engine), and a number of dual-sport type machines - XL600 / XR200 / NX250 Honda, Kawasaki KLR600, the DR, and even one of the old (Italian) Harley XS250 2-strokes, besides V45 Magna Honda cruisers, an early FZ600 Yamaha, etc, etc. I won't get into the Porsche/Nissan/Mitsubishi turbos and other various high-performance cars here, up to 350bhp or more.

With all this to add perspective, let me say that IMHO, pretty much everything starts to feel like a millstone around the neck after a while, everything starts to seem a little stretched on the highway. You become accustomed to even the healthiest levels of acceleration, etc, and it starts to seem mundane after awhile - which is why aftermarket tuners and parts suppliers are running a multi-million (billion?) dollar industry worldwide.

That said, I think the Hero, IF (and only if) well-tuned, is fine within the limits of solo Himalayan riding. The 150 is really a very smooth / refined mill, so while it may start to seem revvy at 85-90kmph (which you will really only see in a couple places in those hundreds of km's from Manali-Leh), it doesn't buzz/vibrate at all. Here's the thing: You learn to work with what you have, to appreciate the places it gets you and its ability to do so, more than any supremacy in the realm of horsepower. For me, a vehicle becomes unsuitable when it forces me to be constantly thinking about its limitations, rather than thinking about the beauty around me. On the outbound trip, the Hero was limiting me; on the return, in a much better state of tune, I was able to let the bike be a little more transparent.

Returning to Manali, I stopped in at the Ride Inn (just down the road from us) for tea with a few fellow detainees from Baralacha-La, and met a girl who is a freelance motorcycle tour leader... she's done Europe to Beijing, even, on a BMW RS1200, and owns an old R80 herself, on which she's done hundreds of thousands of km's. But she's riding a 500cc Bullet here and finding it absolutely fine; and acknowledges that even much lesser bikes can get the job done very well up here. Speeds are just not that high on our Indian roads, and something like my DR would actually end up under-utilized much of the time, and at the cost of fuel efficiency.

Just because a hard-working Brazilian farmer can take his chickens to market with it, doesn't mean it's not suitable for a few other purposes. I'm not going to let those kinds of associations bother me. If it's serving him well, and serving me well, then there's two more happy customers in the world. Bas.

Quote:
Originally Posted by bhogalrajnish View Post
Thanks Eric,

Your post has answered so many questions about carb tuning that I have been looking for answers for a long time now. I have a almost new three year old Karizma guess you have motivated me to start working on it and make it touring capable. Any specific changes you would recommend for the carbed karizma ?
The Karizma has more power than the Impulse, and while good tuning will benefit ANY bike, I've seen a number of stock ones doing Manali-Leh with pillion, apparently without trouble. IMO, tyres are the most important thing out there, since the road surfaces vary so much, and a lot of your time is spent off-pavement. There are some pretty nice, aggressive tread patterns coming out these days, like the Birla Roadmaxx, Dunlop Monster Trail, and a few of the CEAT's. I like to have a good, grippy tyre up front, especially, since having a front tyre wash-out (skid) is a great way to do a serious face-plant.


Thanks to everyone for their interest here.

-Eric

Last edited by ringoism : 19th June 2014 at 10:30.
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Old 19th June 2014, 11:44   #26
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

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Never going to get a bigger engine Impulse. Low cost off road [sic] bikes need volumes to be viable. Not achievable because of the greater seat height. Even given the suitability of the Impulse for our "off road" condition roads! The CRF 250L never took off in Thailand because the average Thai is 5ft3in. High end off road bikes will face the same obstacle : low volumes because of excessive seat heights AND high cost. High end "poser" bikes have a more universal appeal, reflected in viable sales figures.
I suspect you're right, that we'll never get the bigger engine. Also suspect there's more than physiology at play here. One of the other Impulse owners up here is a South Indian teacher girl who commutes between Kullu/Manali and is probably around, well, 5ft3in. tall. Her first bike. She manages it.

Also consider Nepal, where the average human stature is probably measurably less than in India, yet you see quite a lot of dual-sports, especially the XL/XR Hondas and their Taiwanese clones (also saw a KTM and a couple of the rare old Bajaj Endura's in residence north of the border).

Import tariffs (in Nepal, very high whether of Japanese or Indian origin) and volume sales considerations aside, I just have a feeling that the dual-sport "look" has never really connected with the Indian public. On the uneducated rural level, yeah, well, one shocker just seems logically weaker than two in the back; For urban posers, the water-spraying high front mudguard and lack of a center stand just seem too impracticable. But I wonder, too: Does the big suspension and purposeful look actually serve as a constant reminder of, well (ironically), its extreme usefulness - i.e., the deplorable condition of certain roads in even some of the most advanced of our cities... Is it possible that this kind of bike, for the average aspiring urban Indian, represents something excessively rough and unrefined and rural, hearkening back to images of...well - as one poster here mentioned re: the Brazilian Honda Bros the Impulse was based on - farmers taking their chickens to market???

Replacing the KB-RTZ offroad specials - My Hero Impulse-boy-my-dreambike-c3-img14.jpg

I'll admit, my dream bike for a long time was the old, very rural Rajdoot, and if I could've found one up here for sale, I'd have bought it. But I'm a rare bird myself. For now, I eagerly anticipate my arrival, in the course of life and faith, at that point where considerations of "image" and status become completely irrelevant.

-Eric

Last edited by ringoism : 19th June 2014 at 11:53.
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Old 19th June 2014, 22:35   #27
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

I already have a Royal Enfield and have attempted such river crossings before. Somehow the Thunderbird has slight advantage over other RE's out there when it comes to bad roads and overall comfort on highway cruising.

This article/travelogue has now made me ride the Hero Impulse. Will be riding it shortly. Thank you, for such a great write up which has our minds introspecting the true sense of motor cycling.
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Old 21st July 2014, 20:14   #28
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

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Somehow the Thunderbird has slight advantage over other RE's out there when it comes to bad roads and overall comfort on highway cruising.
To me they lack most of the original Bullet's charm, but apart from aesthetics, I'd say the two AVL T-birds I've ridden did strike me as being significantly improved machines in other more practical ways (brakes, gearing, saddle & seating position, adjustable height headlamp, tachometer, etc)... a bike I could probably live with and enjoy, and I might actually like the looks better than the lastest 'birds.
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Old 22nd July 2014, 11:32   #29
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

Well - positive words from you for the AVL Thunderbird makes me further closer to by Motor-Cycle. I have it since Dec 2006 and would like to post a recent picture of the same. Let me know if you are OK with me posting the pic on this thread
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Old 23rd July 2014, 15:24   #30
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Default Re: Replacing the KB-RTZ offroad specials - My Hero Impulse

Update: 2months/2000km:

The KB125 had been sitting forlorn these couple months, completely untouched in the same background position it was photographed at near the start of this thread...

Suddenly occurred to me the other day that its insurance should be running out this month (I intended to keep it current, as a backup), so checked...Mmmm...Already ran out. Rode the Impulse over to the nearest agent, who said he'd start making the papers, but that I needed to bring the bike next day.

So that was my impetus for getting the KB fired up again. Squirted some shock oil in the leaking/clunking RF unit, wiped off the gathering dust / rust with a rag, kicked several times, and was off.

Vs. the Impulse, it now felt strange. Really strange. The rider sits so much lower, knees more bent, with the handle at a further stretch, gear lever higher and shorter. Etc.

But nice. OH.SO.NICE.to.RIDE!!! Had actually forgotten (I was afraid of this) how good it was. Power is so RIGHT THERE - potentially enough to get you beyond your limits and into trouble before you can think - but the torque curve is all quite flat, with so much of it down in the low/mid rpm ranges. Gear ratios are close (remember this had the imported 5-speed set), steering's light, center of gravity's low, suspension's ample travel-wise and at least as compliant as the Hero's while feeling more controlled on rough patches.

So in short, 17-year-old KB (as modified) is still just a complete BLAST to ride - largely because you don't really even have to think about it: It does exactly what you want it to without being dramatic or stressed or really feeling as though you're pushing it hard or being rash (though to bystanders, it probably looks like you are!). Accelerates hard, turns in / brakes so immediately without upsetting anything, responds so willingly when you move your weight around or lean hard into a turn - and does it just as effortlessly on a rough, broken road. Which is to say, it can become simply an extension of the rider's own mind. Just love this thing - This old, cracked, battered, leaking, vibrating, rattling, raspy old thing. But there's the snag. The transparency stops when my ears are screaming for relief.

The Impulse is, well, fine. Does the job and you can actually move along somewhat briskly on it if you want to. Sure is more refined, and there's a measure of "fun" to be had there. But since the power is so rpm-dependent, and the steering so much heavier-feeling, and the chassis so much less responsive to inputs, the difference is that you really do FEEL as though you're working hard - and working the bike hard, too, when riding at a pace that to the KB seems so natural / easy.

So what it needs is what I knew it needed long before I bought it: A little more power, a little less weight (including unsprung, i.e., wheels).

The same day, I stopped by one of the larger local bike workshops and found them working on an Apache 180. Hmmm... has a light-looking little piston that's 62.5mm vs. the Hero's 57.3. Approximately the same stroke on both, so thinking it might be one way to an almost instant 180cc (and some extra compression-ratio) upgrade, assuming the sleeve in the stock 150 cylinder is thick enough to allow that overbore (it would be on a Bajaj 150, but never had one of these Honda's opened up), and the other piston dimensions (pin height, etc) will work. Number of other options along those lines, too: Pulsar180&CBZ (old): 63.5mm = 185cc; Karizma: 65.5mm = 195cc; Duke/NS: 72mm (235cc!!!); etc...

That latter would be overkill, but think I'm going to have to do something here to perk the machine up a little, adding power in the low rpm ranges. Just want to find an old / scrap, genuine HH/H150 jug (cylinder block) and study it a bit to figure out my limits (anyone out there have one, or a picture of one?). It'll be same on Achiever, Hunk, Unicorn, CBZextreme, etc, so hoping to locate something soon at one of the local shops.

There's a U.S. company, Engines Only, who makes a bolt-on 225cc bore kit for the equivalent CRF150f engine; not feeling the need to go that large (nor is it financially feasible), but it indicates to me that the engine cases themselves shouldn't require any machining even for a very large overbore. Compression ratio can be adjusted down if needed by adding block gaskets (or a spacer) or machining the piston crown. Not rocket-science here. I know that on account of its shorter stroke, it still won't likely have quite as much torque as the Karizma engine... But I figure that in the 180-200cc range, it should be plenty for a bike that's 25kg lighter than the ZMA, and still give reasonable average and reliability. Besides, the whole job should only cost me around Rs1000 - very cheap compared to finding a good ZMA mill (plus possible rebuilding) & installation.

Another good thing is that a friend recently gifted me a complete oxy-fuel welding setup that came from abroad. When I say complete, I mean everything needed for welding / cutting / heating (i.e., for bending) a wide variety of types/sizes of metals, besides a fireproof jacket, goggles, regulators, etc. Still need to get the tanks, but once I've got them, I can think about some mods that would require fabrication work, like maybe a free-flow silencer pipe. Let's see.

Next month planning to do Chandra-Tal, an annual event. Kunzum-La is pretty high, and Gramphoo-Batal should be pretty challenging, besides the road to the lake itself. Will update after that, whether I've got my new bore kit or not.

Regards,
Eric

Last edited by ringoism : 23rd July 2014 at 15:27.
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