2 Stroke Top end options? CR125

yawtyler · Apr 26, 2011

Wow, been a while since I've been on DBA. I miss this place.. :cry:

hahaha
but anyway.

So basically i really screwed up when i re-rung my '94 CR125 last fall. Didn't check piston ring end clearance. :doh:

Basically, seized so i tore it down, found out the clearance is off by .006" (six thousandths). So basically, what's my best option? I've thought about a .020" overbore, but would that require replating? I'm not sure how thick the Nikasil is on these things. Could I shave off .006" from my ring to make it fit? Thought I'd ask before really screwing myself up more here. haha

Thanks for any ideas/opinions!

yamadogyz · Apr 26, 2011

You finally come crawling back :lol:

Wish I could help

Mihylo33 · Apr 26, 2011

Yes its called setting the "Ring End Gap"... There should be instructions telling you how to do so with your wiseco piston kit. basically you file the end of the rings until they meet spec.

yawtyler · Apr 26, 2011

Well i mean, i know you can do it, but i wondered if .006 was too much to file off? i'm thinking it's not.
Is there a way to find those instructions? I took the cheap way out and just ordered a ring.. :smirk:

Mihylo33 · Apr 26, 2011

Wiseco.com

yawtyler · Apr 26, 2011

Probably should by a new ring. haha, crap.

Mihylo33 · Apr 27, 2011

post a pic of your cylinder interior. It may need replating.

yawtyler · Apr 28, 2011

I was thinking that, but i'm not sure. God i hope not, that's costly haha. Here's pics of my cylinder though. I think it looks pretty good..except for one possible problem spot. Lemme know what ya think.

Aaaand, this spot here i think might be an issue..not quite sure.

Mihylo33 · Apr 28, 2011

Its worn, but you might get away with it... did you drill the piston for the exhaust port bridge?

yawtyler · Apr 28, 2011

Yeeeup. Well the guy before me did at least. haha
Probably ordering new ring next week. Prom is this weekend, if I have ANY money left it's going RIGHT into my bike!! :smirk:

jackson409 · Apr 28, 2011

yep the ole famous exhaust port,, honestly some people relieve them so they dont make some much contact with the piston, I wouldn't mess with replating that. drill new holes or relieve it and your good.

Mihylo33 · Apr 28, 2011

jackson409:
yep the ole famous exhaust port,, honestly some people relieve them so they dont make some much contact with the piston, I wouldn't mess with replating that. drill new holes or relieve it and your good.

Just came from a buddies house that bought an 04 with a fried topend.... same thing. his needs replating.... lol