[srini1785]

Originally Posted by ashwinprakas

That my friend is a backfire!

Reasons:
1. You're running absurdly rich.
2. Your choke circuit is open.

EDIT:

Sorry, I missed to take the age of the motorcycle into consideration.

Please make sure your valves are operating as expected, a decent means of ensuring the same would be to conduct a compression test. A backfire can also be caused by the intake valve not sealing properly and Honda’s are known for stuck valves.

Thanks for the advice. By " Compression test", i guess you are asking me to check if there is alternatively vacuum and compression on the cylinder when the pistons move?. i did put my thumb on the spark plug hole and checked earlier and it did seem to perform properly. However , i will check once again and try to open the cylinder head to see if the valves are opening and closing properly too.

[ashwinprakas]

Originally Posted by srini1785

Thanks for the advice. By " Compression test", i guess you are asking me to check if there is alternatively vacuum and compression on the cylinder when the pistons move?. i did put my thumb on the spark plug hole and checked earlier and it did seem to perform properly. However , i will check once again and try to open the cylinder head to see if the valves are opening and closing properly too.

Unfortunately that won’t do, you would need a compression gauge to perform a compression test. First you would need to find out what the factory rated compression for the motor is, then you'd have to check your motorcycle and see if it falls within the recommended range. If yes then you can move on to diagnosing the fuelling, if not then first make sure that the piston and rings are fine and then do another compression test, if you are still not within recommended range then you would need to overhaul the head.

[james]

Suggestion: Fill in fresh engine oil. Put in a tiny bit of oil down the spark plug hole and then check the compression with a gauge. It should be 160+ PSI and almost equal in both cylinders.

If you got the bike without spark plugs or carbs or exhaust bend pipe in place, i would suggest opening and cleaning up the top end. You dont know what may have gone in there over time. Even the slightest bit of sand or mud is enough to ruin the motor. This way you can ascertain the condition of the liners as well. You will need a new packing kit to put the motor back together.

Cheers!!

[srini1785]

Its been sometime since I updated this thread. I have not been able to do much on the bike since I was held up trying to start a TVS Suzuki supra power up model. However , I did manage to open the top cover and check the timing belt and valve seat. I have posted a video on this link

https://youtu.be/roKZVksGtj8

From what I have read online, this model seems to be a parallel twin. However , when you see the valve timing sequence, it seems to me that only one cylinder fires at a time. Am I correct?.

Meanwhile , I have got the upper sealing kit and have ordered the lower sealing kit. This next step is to just take the engine off the frame and check the valve timing.

[MonsterPatrol]

Nothing like finding a CBX 1000, the ultimate collectors bike for a Retro Bike enthusiast like me. Extremely hard to find though. I remember seeing an for it a couple of years back on Facebook. The dude was quoting FIFTEEN LAKHS!!

[srini1785]

Some Updates regarding the restoration. The bike is now painted and mechanically complete. The backfire issue has been sorted out. It was due to improper timing. The bike has been rewired. The cylinder head was also machined and now the engine starts without problem. However, it is still not a rider since there is a un pluggable leak from the front sprocket oil seal. By leak I don't mean a drop or two , it just pours.

I tried to find a suitable oil seal locally and also bought two of them from UK but no avail. I need some help in locating a suitable seal. The size I bought ( the one that came from UK claiming to be OEM seal ) is TC 20x34x7. I need to find a seal that is at least TC 19x35x8 if it is available. I also tried Anabond red quick seal maker with no luck. Any suggestion on how to select a suitable oil seal would be welcome.


Further , just wanted to know if the oil pore on the drive shaft ( pictured ) needs to be plugged or kept open?.

[MonsterPatrol]

I was offered an XJR 400 inline four. Bike looked okay but the non availability of parts was a big issue. And the price was ridiculously high.

[srini1785]

Some updates from my side.

After breaking around 8-10 plugs, found the proper plug and now the bike starts and runs. Though far from complete. A royal Oilfield , this bike. Leaks oil from case, forks and wherever possible.

Starting Video.

https://www.youtube.com/watch?v=XcornERggC0

[Ajaybiz]

Dont take me wrong but this is not at all running properly, any twin or even inline 4 ideals very smoothly. Those indicators, CD100 meter, that head light, wrong side of tank mono gram these all are making it worse, get some old skool bike restoration specialist, source parts from south east asian countries and make a real CD 185, this looked more like pain to ride and no road presence.

[srini1785]

Yeah i know. Those indicators and meter assy are not original and are from RE and CD100. This one was half buried in ground when i got it. Idea was to get it to run with whatever parts available and then change over to genuine ones. Had a tough time finding a mechanic who would take this bike. No one was interested. It took me 2 years just to get it started and running. That's why i said its far from complete. Still some issues as i pointed out, mainly with leaks will sort it out soon.

[ashwinprakas]

Originally Posted by srini1785

Some updates from my side.

To hell with the finer details, as long as the motorcycle is firing and road worthy all is well in my books.

If the leaks aren't concerning then I'd start clocking miles on her and fix the finer details as and when time permits, in fact my P220 has been leaking oil from the same places for the past 40k km's.

BTW, do share specifics regarding how you managed to set up the ignition and other alternative fixes. And what firing order is she running? Yesterday I was reading up about the Big Bang firing order and its traction benefits and came up on some text that mentioned that riders with parallel twins would make sure both cylinders fired simultaneously to mimic the traction benefits of the Big Bang firing order.

Do keep us posted and Congratulations on the revival!

Cheers,
A.P.

[srini1785]

Originally Posted by ashwinprakas

To hell with the finer details, as long as the motorcycle is firing and road worthy all is well in my books.

That was the idea. However to Ajay's post credit , i must admit in all honesty he is right. I too was not really sure if it was firing right and first impressions do tell the truth. When this video was shot ( around 2 months back), she was running on a splendor carb ( with wrong jetting ) and a UR4AC Bosch plug. Both of which were wrong. I have since replaced the plug with a NGK iridium and worked better actually. I am yet to get the actual CR7HS NGK plug which is the recommended plug for this Bike.

Originally Posted by ashwinprakas

BTW, do share specifics regarding how you managed to set up the ignition and other alternative fixes. And what firing order is she running? Yesterday I was reading up about the Big Bang firing order and its traction benefits and came up on some text that mentioned that riders with parallel twins would make sure both cylinders fired simultaneously to mimic the traction benefits of the Big Bang firing order.

This is a parallel twin. Both pistons move simultaneously however only one fires at a time even though there is spark on both cylinders. The OHC settings controls which cylinder fires. I changed from the old points set (6V) to CDI (12V) and use a NS200 ignition coil.

With block and head removed:


This is what happens to the head when you use the wrong jetting and plug.




The block is carbonised when the plugs are not of right temperature class.

[Dressellian]

I found this thread while looking for views about the newly launched Honda CB350.
What do you guys think of the new motorcycle that reeks retro?

[Vmax1200]

I am waiting for Honda CB1100. Perfect bike for India.