Engine Noise? 2001 Honda CR125R (video)
Posted 05 May 2012 - 07:25 AM
It's an 01 that I picked up a few months ago. Ridden twice and seems to run fine despite this noise. I'm afraid it will cause (more) damage if I continue to ride. Looking for help as to what needs to be rebuilt.
Posted 05 May 2012 - 09:03 AM
Edited by AXAxiom, 05 May 2012 - 09:06 AM.
Posted 06 May 2012 - 03:10 AM
There was side too side play on my rod, but no up and down. So now I have peace of mind, but if I was you I would just ride it untill you plan on doing a topend and inspect everything while you're there.
Edited by noysy1, 06 May 2012 - 03:13 AM.
Posted 06 May 2012 - 03:45 AM
Yes this. Its sounds pretty normal.
Posted 06 May 2012 - 07:37 AM
Posted 06 May 2012 - 07:46 AM
Posted 07 May 2012 - 03:26 AM
Posted 15 May 2012 - 05:41 PM
Regardless, I ordered a new top end and hope to put it in this weekend. It has an ART piston right now. I have an A cylinder and will be putting a C piston in. Previous owner only had it about a year and did not do a top end. Said guy he bought it from did one before PO bought it. Cold compression check was about 120 psi on a good gauge.
I'll keep you posted. Thanks all for the input.
Posted 15 May 2012 - 11:09 PM
Posted 16 May 2012 - 11:55 AM
So, take your cylinder and piston off and remove the ring from the piston. Stick the piston in the cylinder and shake the top of the piston at various places in the bore. It gets noticeably looser in the exhaust port area. The noise is the piston rocking in the bore because the bore is so out of round and they come that way from Honda. You can get your cylinder replated to straighten out the bore or simply get a ProX incremental oversize piston to tighten up the clearance. They have four sizes and I've had good luck the the third oversize in all four of my CR125's. Good luck...
Posted 17 May 2012 - 04:33 AM
Float, I'm hoping the larger piston will do the trick. I have a C piston (53.96mm) being shipped now. I'll try your ring-less piston check when I do the top end.
I've had other riders suggest the bottom end bearings, reeds, fuel mixture, oil level ... you name it. Was hoping to get a definitive diagnosis online here. I'll post my troubleshooting to hopefully help the next fellow out.
Posted 18 May 2012 - 09:09 AM
I tried but I didn't trust it. I measured like 53.7mm with my Harbor Freight digital caliper. I'm guessing it should be high 53.9 though since the piston is already that.