Jump to content
Sign in to follow this  

Slight Knocking/Tapping

Recommended Posts

Hey guys just a quick question! My new to me '09 DRZ400SM has 2500mi on her and I noticed that in when I first take off and have the clutch out partially I get a slight knocking/tapping noise from motor. Is this normal? It's doesn't make the noise when clutch is fully disengaged or at speed soooo........?

Share this post


Link to post
Share on other sites

Could be piston slap , if you are using not enough Revs to pull away .

Is your idle really low ?

piston slap? No the Rpm's are just fine at idle. Maybe I'll try and post up a vid later today. Might be tricky since it only does it under slight load with me on bike

Share this post


Link to post
Share on other sites

Hey guys just a quick question! My new to me '09 DRZ400SM has 2500mi on her and I noticed that in when I first take off and have the clutch out partially I get a slight knocking/tapping noise from motor. Is this normal? It's doesn't make the noise when clutch is fully disengaged or at speed soooo........?

 

is your chain tension set correctly ? 2500 miles is about right for it to be getting fairly slack, and that slack will end up slapping the top/bottom of the swingarm at very low rpms, or while lugging the engine. 

Share this post


Link to post
Share on other sites

I've been going crazy about this since I got the bike, so I did all the fixes, got rid of the decomp, but the noise just was still there. I finally arrived at the conclusion it's the carb slider rattling, when I got hold of a spare carb, tapping the slider with my finger I got exactly the same noise. It's at its loudest at low revs because that's when the slider is down, as it moves upward there's less rattle. Nothing to worry about if it's your case. Had the same pŕoblem with my old XT600, for that I had teflon sliders made, that solved it, but in this case the slider shape is too hard to replicate.

 

Mine's a Mikuni, but I also have a spare Keihin that makes much the same noise if I tap against the slider.

Edited by michaelks

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×