wr400 pinging


6 replies to this topic
  • holdon

Posted March 15, 2007 - 07:38 PM

#1

hi there. i have recnetly bought a wr400 2000 model. since i got it i have noticed a rattle noise comig from the engine. now it sounds like it is pinging to me. noise seems to be coming from the top end and more noticable on the left hand side of the bike (if sitting on it)

some background info.

it does it in any gear (higher gears more noticable)
does it at the same RPM regardless of gear (low- mid range)
does it even when NOT underload (down a hill) (worse tho when underload i think)
bike is running high octane fuel
does it when cold/hot
happens only at a certain rpm and goes away when revs drop/rise just that little bit.
motor revs/idels/starts very well. no other noticealble noises.

now.....i have done some searched on this site and some ppl said to check chain tension. my chain IS a little loose - but i dont see why that would be the problem as it only makes the noise at a certain RPM and reglardless of gear.....

im yet to rev the engine slowing in neutral to see if i can hear it at the same rpm....

does any one have any ideas of whats wrong? or what i can do?

thanks!

  • SXP

Posted March 15, 2007 - 09:20 PM

#2

hi there. i have recnetly bought a wr400 2000 model. since i got it i have noticed a rattle noise comig from the engine. now it sounds like it is pinging to me. noise seems to be coming from the top end and more noticable on the left hand side of the bike (if sitting on it)

some background info.

it does it in any gear (higher gears more noticable)
does it at the same RPM regardless of gear (low- mid range)
does it even when NOT underload (down a hill) (worse tho when underload i think)
bike is running high octane fuel
does it when cold/hot
happens only at a certain rpm and goes away when revs drop/rise just that little bit.
motor revs/idels/starts very well. no other noticealble noises.

now.....i have done some searched on this site and some ppl said to check chain tension. my chain IS a little loose - but i dont see why that would be the problem as it only makes the noise at a certain RPM and reglardless of gear.....

im yet to rev the engine slowing in neutral to see if i can hear it at the same rpm....

does any one have any ideas of whats wrong? or what i can do?

thanks!


How old is your chain? Does it have a lot of uneven spots (tight in some spots and loose in others)? I'll almost gurantee it's your chain rapping on the slider that's causing the problem. Before you start tearing into things I'd suggest you replace your chain and sprockets especially if you are due.

  • brt 426

Posted March 16, 2007 - 12:44 AM

#3

Hello Holdon,
I recently purchased a 01 426 not running.
When I stripped the top end, I found the cam chain had stretched and jumped a tooth on the crank sprocket. The cam chain lives on the left side of the engine. I believe the noise you can hear is the cam chain.Pinging would only be noticeable on acceleration. And more at the low end of the rev range with a large amount of throttle. And most likely with a lower grade of fuel.
P.S The inlet valves clearances had closed up also .Re-shimmed and new cam chain. Away it went . It does blow a bit of blue smoke but it was cheap enough. Let me know if this helpful .

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  • holdon

Posted March 16, 2007 - 09:53 PM

#4

well i have tightened up the chain the noise has dropped substantially. so i guess that was it! there is still a quiet rattle there but the chain/sprockets are due for replacement.

thanks for all your help!

  • SXP

Posted March 17, 2007 - 08:04 PM

#5

well i have tightened up the chain the noise has dropped substantially. so i guess that was it! there is still a quiet rattle there but the chain/sprockets are due for replacement.

thanks for all your help!


You are welcome. The residual racket is most likely due to an unevenly stretched chain. Change it (and sprockets).

Isn't it freaky how similar to pinging the chain slapping on the slider sounds? I had the same issue and one of our TT brethren from "down under" set me straight.

Oh, and if you haven't already, do the swingarm mod - some form of sealant under the slider to provide a cushion. This greatly reduces the chain slap noise.

  • Thermos O flask

Posted March 18, 2007 - 02:31 PM

#6

Do the chain slider mod straight away,i could never work out why the chain master link was wearing and what the noise was.I did the chain slider mod..perfecto!!:

  • brt 426

Posted March 18, 2007 - 03:07 PM

#7

Hello Holdon,
Sorry if I tried to mislead you with that advice I offered. After riding our 426 on Saturday for the first long period of time. I noticed the sound that you where refering to. Ours makes that same noise. It's quite annoying how it cracks away. I'm going to adjust the chain and see if that helps also. Thanks for starting this thread




 
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