Thumping felt while coasting......output shaft problems?

[jax]

As a few of you may know my bike has the YZF rear conversion. This morning I noticed a thumping noise and felt it while coasting into the gas station. Under acceleration it can't be felt. I can feel it on the footpegs when coasting so I am thinking maybe its the output shaft. I came in here to get some input on what to look for.

I plan on doing the following.


Remove the clutch mechanism cover and inspect the sprocket and check for slop in the output shaft.

Lube the chain real good and see if maybe its a slight kink in one of the links.

Inspect the rear wheel bearings.


Anything else I should be maybe looking at?.......

Thanks guys

[yamaha_george]

As a few of you may know my bike has the YZF rear conversion. This morning I noticed a thumping noise and felt it while coasting into the gas station. Under acceleration it can't be felt. I can feel it on the footpegs when coasting so I am thinking maybe its the output shaft. I came in here to get some input on what to look for.

I plan on doing the following.


Remove the clutch mechanism cover and inspect the sprocket and check for slop in the output shaft.

Lube the chain real good and see if maybe its a slight kink in one of the links.

Inspect the rear wheel bearings.


Anything else I should be maybe looking at?.......



Thanks guys

I would also be looking at the conversion for play since that will only show up as a problem when not under power

[reelrazor]

As a few of you may know my bike has the YZF rear conversion. This morning I noticed a thumping noise and felt it while coasting into the gas station. Under acceleration it can't be felt. I can feel it on the footpegs when coasting so I am thinking maybe its the output shaft. I came in here to get some input on what to look for.

I plan on doing the following.


Remove the clutch mechanism cover and inspect the sprocket and check for slop in the output shaft.

Lube the chain real good and see if maybe its a slight kink in one of the links.

Inspect the rear wheel bearings.


Anything else I should be maybe looking at?.......

Thanks guys

My bet is the chain/sprocket setup. Maybe a bad link or two...maybe a worn sprocket(front esp.)..maybe bad cush drives.

[jax]

I'll go over the conversion again and make sure everything is buttoned up the way its supposed to be. I took a peek inside the front sprocket area and didn't see any oil leaking. My tendency is to think that if it was a problem with the output shaft the shaft bearing seal would go first and start leaking oil.

The rear sprocket shows no sign of wear as I have cleaned it off and inspected it. I have yet to look at the front sprocket.

I'll remove the chain and check for stiff links. I did notice the master link had a bit of rust on it since last time I rode the bike it rained. Maybe thats my problem. I'll keep you guys informed with what I find.

[manveru]

i maybe out in left field but have you checked the clearance of the chain and foot pegs? if i remember right with the yzf swingarm they had to be spaced out or clearanced. could be that under deceleration the chain is getting slack and rubbing?

[jax]

i maybe out in left field but have you checked the clearance of the chain and foot pegs? if i remember right with the yzf swingarm they had to be spaced out or clearanced. could be that under deceleration the chain is getting slack and rubbing?

Good point. I know the chain is very close on mine. Thanks for the input.

[apsolus]

manvaru might be on to someting. i had that same prob with my 600 no conversion its just the chain was to wide and hit the foot peg, and like you, i could only be heard slowing down. hope thats the problme

[Model192]

Had the same problem without a conversion, was just the chain. They get tight/loose spots, time for a new one probably.

[jax]

Well guys the best possible scenario played out for me luckily. I got home and put a jack under the rear suspension and raised it just a tad to clear the rear wheel. Spun it and I was able to feel the rough spot / thud. It was right at the master link. you could see a kink in it. My dumb arse didn't lube it after I rode it in the rain a while back. It just needs a good cleaning and lube.

I removed the chain and it is soaking overnight in some silicone based WD40 type lube. In the morning I will blow off the excess with my air compressor and reinstall the chain. Give it a good twice over with some PJ1 lube and I should be good to go.

I'll keep you guys posted if that doesn't solve it.

[sweekster]

[jax]

Rode it in to work today. Problem is gone. Just have to remember to mind the chain after I ride in the rain. I also got around to checking all the bolts and everything related to the swinger swap. All was good. The safety wire on the front sprocket is holding as designed.

Thank you to all who pitched in with the ideas. To show my gratitude I went ahead and made a donation to the site as I have gained knowledge from here and have received help from others. I encourage everyone to donate a bit even if its a couple of bucks.

[yamaha_george]

Rode it in to work today. Problem is gone. Just have to remember to mind the chain after I ride in the rain. I also got around to checking all the bolts and everything related to the swinger swap. All was good. The safety wire on the front sprocket is holding as designed.

Thank you to all who pitched in with the ideas. To show my gratitude I went ahead and made a donation to the site as I have gained knowledge from here and have received help from others. I encourage everyone to donate a bit even if its a couple of bucks.

Jax,
Thank you for the donation, T o keep the site going I tend to send mine on it s Birthday every year, I figure if everyone donated a buck a month at that time for the following year we could add other stuff to the site as well

My other point to you is if you are using an " O" or "X" ring chain be careful of soaking in the wrong kind of solvent and no matter what chain NEVER use an air line t o force crap between links & under the sealing rubber rings.

I w ill repeat what I wrote a short while back that chains should be sprayed at the end of the journey (when hot) NEVER be washed with a pressure washer (see air line above) and if it does get rusty then greasing it etc will turn the iron oxide (rust) in to fine grinding paste and will wear VERY quickly .

If you put the bike into mothballs for the winter take the chain off and submerge it in clean non additive engine oil,

[jax]

Thanks for the input G. I took the advice from one of the R6 boards I am a member of and sprayed down the chain with spray lubricant. I didnt think anything of the compressed air but i see your point. Hopefully the shower of PJ1 I gave the chain will mitigate any potential damage I might have caused.

[yamaha_george]

Thanks for the input G. I took the advice from one of the R6 boards I am a member of and sprayed down the chain with spray lubricant. I didnt think anything of the compressed air but i see your point. Hopefully the shower of PJ1 I gave the chain will mitigate any potential damage I might have caused.

Jax,
well there are not too many "old geezers" around riding R 6 or any modern bike for that matter ( they mostly hang out on old bike forums talking about the "glory days of old brit bikes" & such ) as dumb as i am I did learn a few things in 50 + years of biking and wenching

EDIT: -
sorry spelled that wrong but I cannot find the tippex

[jax]

Cheers............



Thanks again.