Jump to content

shimming a motor

Recommended Posts

I read where people were shimming a 2-stroke motor to make it vibrate less. Does shimming a motor really cut down on motor vibration and if it does work, will it work on my 2007 HONDA CR125 and what would I have to do to shim my motor....

Share this post


Link to post
Share on other sites

You must have something else going on for a small bore to have a bad vibration, unless it is inherit to that model. I don't have a clue about the shimming you speak of...and I have been turning wrenches on MC's for over 30 years.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for posting back. My bike doesn't vibrate bad. I was just wondering if shimming a motor did cut down on the vibrations. I think the article I read was on a yz250, and they talked like it helped.

Share this post


Link to post
Share on other sites

I think they put washers or spacers on the motor mounts, and or the swing arm, and maybe the head stay bolts too. Wish I could remember where I read this at......

 

  • Like 2

Share this post


Link to post
Share on other sites

I don't think I read the article,  but if there is room for  a shim,  washer etc when the motormount bolts or the swinarm pivot bolt is loosened or removed,  you can get a reduction in vibration.  That can come with a trade too though.   (on and older flexed out frame,  the mounts on the engine can break if there is no movement at the bolts,  but I have seen very few times.  More often you get head gasket leaks.)

Share this post


Link to post
Share on other sites

I also think if the vibration is that noticeable, you most likely have something inside the motor going bad. When I first bought my CR250 it vibrated quite a bit and caused my hands to go numb after riding for a while. I eventually lost a piston skirt (my fault) and while I had the engine apart I decided to rebuild the bottom end as well since I was unsure of if it had ever been done. I sent my factory Honda crank out to Ken O'Connor racing for a rebuild. When I got it back, the engine was silky smooth. The vibration I thought was normal was GONE. So, another vote for "internal engine problem".

  • Like 1

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:


×