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Noise, I'm stuck...

Posted: Sat May 17, 2014 3:40 am
by Lundiegge
Looking for help, been on the TT forums but looking for help anywhere I can.

50 hours on new top end, stainless steel valves, valves adjusted (and rechecked), cam chain and guides are good. Primary ignition coil resistance at 0.5 (should be 0.1-.3), any help? Check the video:

https://www.youtube.com/watch?v=aYrnwP6mOfg

I'm in Senegal, local dudes helpful but don't know the bike.

Thanks.

Posted: Sat May 17, 2014 8:20 am
by MikeOK
There is a similar thread over on tt about this. Sounds like your decompressor arm is not moving out of the way.

Posted: Sat May 17, 2014 10:12 am
by Lundiegge
Thanks, I'll search TT.

But if the decompressor arm was not moving out of the way wouldn't that mean the plunger would always be extended and keep popping the exhaust valve open and then reduce compression and affect how the bike ran? or not? Bike runs great, just the noise. It's a 2008, centrifugal force makes the decompressor weight move outward and the plunger drops...right? I don't get what can stick?

Thanks, Steve

Posted: Sat May 17, 2014 2:17 pm
by madmax
Check your cam chain tensioner. They sound like that when they go.

Pull it off and see if you can push in the plunger, if you can then it`s bad.

Posted: Sat May 17, 2014 2:29 pm
by Lundiegge
Just found a few copper flakes in the oil....I fear the worst.

Posted: Sat May 17, 2014 4:25 pm
by MikeOK
Oops copper flakes... Here is the link I mentioned:

http://www.thumpertalk.com/topic/108583 ... dc-normal/

Posted: Sat May 17, 2014 7:28 pm
by crfsonly
just read through that post quickly but if you are missing a shim you MUST find that shim before you run that motor again. it will eventually find it's way to a moving part and when it does there will be very expensive damage. also, if you have been running without a shim you will have damaged the retainer and the top of the valve. you'll need to replace them both. if it's on the exhaust side you damaged your rocker arm as well. if on the intake you likely damaged your shim bucket. if your valve(s) have gone to zero you need a valve job and new valves.

copper/bronze colored metal shavings are an indication your thrust washer are bad. only way to fix that is to split the cases.

ken

Posted: Sat May 17, 2014 8:28 pm
by MikeOK
I agree I would worry if I had a missing shim like that guy found. Am I correct that the valve clearances that we check get tighter with wear instead if looser? If that's the case I wouldn't think you would get the noise like is in this poster's video because of valves.

Posted: Sun May 18, 2014 7:37 am
by JimDirt
MikeOK wrote:I agree I would worry if I had a missing shim like that guy found. Am I correct that the valve clearances that we check get tighter with wear instead if looser? If that's the case I wouldn't think you would get the noise like is in this poster's video because of valves.


Yes your correct , the clearance gets tighter as the valve wears , it gets thinner where it contacts the seat , and the valve moves closer to the cam lobes reducing the gap , so it will NOT get more noisy as it wears

Posted: Mon May 19, 2014 4:10 am
by Aussiecrf230
Unless it wears a lot and goes bang.
Fortunately Hondas refuse to start when worn.
Yamahas tend to go bang resulting in a new head and barrel as well.