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-   -   Funny problem with Yamaha RXZ (https://www.team-bhp.com/forum/motorbikes/43513-funny-problem-yamaha-rxz.html)

Hey guys. I have a '97 RXZ 4 speed. For the last couple of days there has been a funny problem with the bike. Every time I go above 3.5k rpm in any gear, the engine kind of stops accelerating and behaves as if its hit a rev-limiter. It starts jerking like it would if the petrol was getting over. Initially I thought the carb was clogged. I tried to clean it by blowing into it, but that did'nt work. I thought I'll get it properly checked later.

What has got me really worried now is that when I was going up a flyover slope this morning the engine almost completely lost power and there was a kind of pheensh-pheensh funny whistling noise coming from the cylinder. I needed to shift down to 2nd to continue climbing. As I reached the top of the flyover, this sound stopped and but it continued to run at the 3.5k redline, not allowing me to accelerate beyond 55kmph.
I am now beginning to think that there could be some piston/piston ring damage. The engine had seized about 2 years ago, and had its first upsize then. I also have a K&N filter which is partially uncovered. Could the problem be due to water getting in from this?
I also need help in selecting a good mechanic in case it is a complete engine job as Im beginning to suspect. I've been in Bangalore (living in Kormangala) a little over a month and dont have too much of an idea about the good mechanics here. Any help will be much appreciated!

Before suspecting engine (cyl/piston/rings) I would check the follwoing and recitfy/replace if found faulty;
1. Clogged air filter - clean it.
2. Faulty spark plug - clean/replace it.
3. Ignition coil (happend many times with my RX, Shogun and once with my Bullet) - replace.
4. Carb - clean it.

All the 4 things above mentioned can cause a starving effect on higher RPMs

the funny sound you mention could be due to
a) the spark plug not tightened properly, or
b) leakage from the head gasket.
make sure that both are torqued down to specifications and the head gasket is not blown.
cheers

The carb I have tried to clean myself, maybe it requires a professional to do it with a pressurised hose.
I have cleaned the spark plug tip and refitted it. This too to no avail

The other suggestions probably have to be done by a mechanic. Can anybody help me with a good one in or around Koramangala. Thanks!

Looks like low compression engine, get checked the compression, clutch plates, one guy called Balaji works near Koramangala Club search for him and get it done if you are in budget.
If expences are getting too much than dont spend on repairs, convert her to 5 speed gear box with new cylender block set.

i had a similar problem that turned out to be the CDI problem. i think the first reply is a good one you can work towards that. consulting a good mechanic always helps

Blowing into carb ?
You need to take it off the bike , open up the float bowl and do a thorough cleaning job. And use some de-carb spray also.

But it doesn't sound like a carb problem by your description.
Maybe a leaking head gasket but that wouldn't "limit" you to 3.5K RPM AFAIK.

Electricals might be an issue and also try cleaning the air filter and fuel line.

Simplest job would be to take it to a decent service station or mech. You can try this - Bikeworld.co.in,Bike World,Bike,World,Bikeworld,Bike world bangalore,bikeworld bangalore,motorbike service,motorbike services,bangalore motorbike service,dirt motorbike service,motorbike fitting services,scooter service,scooter services,bangalore sco

The one in Jayanagar has good mechs. I get my bikes done from them. But its far from your place. They have branches in other areas too. check out the website.

Download the manual
http://www.team-bhp.com/forum/collec...e-driving.html

Compare the condition of your sparkplug against the pictures in the manual.
Say thanks to the guy who uploaded the manual.

btw a new spark plug costs less than 100 bucks.
Replace and check.

Hi PhrozenFire, is your problem occurring only under load ?

Or does the issue manifest even if the engine's revved in neutral ?

I'd start with checking out the jets to see if they've been blocked by any debris.

Second, ensure your timing advance is working as it should.

Most probably a leakage in the head.
Check for-
Blown head gasket (especially if you didn't change it the last time you opened the head. Most lay mechanics don't replace it and it gets very flat and doesn't provide proper sealing over time.))
Check for leakage from near spark plug- rare unless spark plug over-tightened and threads worn out
Head stud/s threads worn out causing a loosely-fitting head
Or threads on the block where head studs fit worn out- will require rethreading and fitting oversized studs.

I used to lap the block and head of my 4-speed RX-135 for perfect fit + slightly more compression and then used the oem copper head gaskets and not the local aluminium ones.
The stocks studs (1-2 gave up) and i had a tough time riding it back from a inter-city trip, with the bike bucking, wheezing and barely making enough power to move.
Had to keep the revs low, else that phheenshh-phheenshh (nice imitation buddy:uncontrol) and huge loss in power.
Rethreaded the block and fitted oversized studs but the poor quality of the block metal led to the threads getting worn out very soon due to higher compression.
Finally got brass sleeves threaded into the block and then used stock size head studs- no issues ever again .:)

Another issue of not making enough rpm aqnd bucking/wheezing, though phheenshh-phheenshh suggests head leakage in your case, maybe a bad ignition/cdi coil.
Do you have starting issues since sometime?

Hey all,
First up thanks for all your comments and suggestions. Hadn't thought of quite a few of the things that you guys suggested.
Didnt come across any details about any other branches on the website. Do you know of any? Have taken down the contact no. Will call up and ask.

My spark plug is about three months old. Dont think there's a problem with that. Refitted it and checked.

Nope, it happens only in gear. Its not as pronounced in neutral, but yes it doesn't rev smoothly, as it should be.

Leakage from the gasket/blown head is the feeling I was getting too. No starting problems whatsoever. One kick start everytime :).

Ok, update since yesterday. While riding back home around 9PM last night, with all these possible issues swimming around in my head, the bike was behaving exactly like it was in the morning, with the revs dying after 3.5k and yes, bucking and wheezing as Bikenstein described. Then with an almighty blast something was expelled from the exhaust. Breathing a huge sigh of relief (almost like the feeling of a very satisfying fart after a long bout of constipation:uncontrol), I thought maybe it was just dirt in the carb after all. I tentatively opened up the throttle little by little. Everything seemed to be ok till I reached traffic. The bike was revving easily till 5-6k by now. In traffic everytime I was accelerating in 1st gear, the engine was dying. I had to keep the revs really high in order to keep going. But this was only in 1st. Even if the revs dropped in 2nd, 3rd gear, the engine was still going. And so it was today morning also. Only in 1st gear, with the clutch half pressed and while accelerating the engine would suddenly just die leaving me kicking in the middle of the road with traffic behind. I'm now at my wits end about the issue could be!
Still a carb problem??

I had a similar problem on my bike, turned out to be the crab. The mech also replaced the sparkplug. Your spark plug could be overheating.

I suggest you give your bike to Castrol bike zone

I've heard that they're good. Have seen a lot of Pulsars and ZMAs parked there. Are they good with two-strokes also?

i think the problem should be ratified considering 3 things 1)getting the carb tunning checked 2)getting the coil checked or by 3)getting the clutch checked. I dont suspect there is a problem with the bore and piston(unless your engine has done around 50000 after upsizing). Replace your filters with the stock one.Gurus, please correct if im wrong.:)
I think getting the job done in the showroom is better. There are other places like DTW and Pacer Yamaha.

Na Na. Bike Zone in Mysore road and Bike Zone in JC Road and also the one in Rajajinagar- they are really bad ..not just with 2 strokes.

FYI, Bike World was setup by former franchisee holders after the Castrol Bike Zone franchisee had some problems and led to its partial break-up. They do a good job. Particularly the one near Jayanagar 7th block.