midnighttoker Posted February 19, 2004 Report Share Posted February 19, 2004 i was wondering if boaring is needed when ever something happens in the cylinders. i blew one of my crankshaft bearings and it shot metal in the cylinders. when i took it all apart i know im going to need new pistons and a new head but the cylinders didnt get that tore up. the biggest scratch is about an inch long and has to be less than a millemeter deep. do you think it would be ok if i just got new pistions and left the cylinders as is? ohh yea i was wondering too how i can tell what size pistons are on it now, there was a number on the top of the pistion but i didnt know what it meant....(513mb6400) Quote Link to comment Share on other sites More sharing options...
sredish Posted February 19, 2004 Report Share Posted February 19, 2004 the biggest scratch is about an inch long and has to be less than a millemeter deep. No. Nope. No way. Do not think that a scratch, especially a millimeter deep is okay. That will need to taken out, I wouldn't even think about maybe trying it. A millimeter compared to the tolerances in the cylinder is HUGE. You bore when your cylinder is worn enough that the standard bore (or whatever bore your on) is worn enough to prevent the cylinder from making adequate compression, or you have a scratch a millimeter deep. If you don't know what size pistons are on it. Take it to the shop to perform the top end and let them measure the diameter, they'll know what size bore is in it, and what size to step up to. Quote Link to comment Share on other sites More sharing options...
wheeleymaster99 Posted February 19, 2004 Report Share Posted February 19, 2004 yeah if theres a scrach biggenough to see you will need to do something about it Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted February 19, 2004 Report Share Posted February 19, 2004 i agree. dont run that thing with a scratch in the cylinder. if you do, youre just asking for trouble. Quote Link to comment Share on other sites More sharing options...
bigboybanshee Posted February 19, 2004 Report Share Posted February 19, 2004 (513mb6400) I'm no genius but I'd be willing to bet you have a 64mm bore from looking at the numbers you posted...and yeah, I'd definitly bore that sucker the next size up. I'm running a 65mm bore right now, .040 over pistons are what fit it...hope this helps! Quote Link to comment Share on other sites More sharing options...
silveradohd Posted February 20, 2004 Report Share Posted February 20, 2004 You should really spend the extra $90-100 dollars to get that scratch in there. You can't really cut corners with 2 stroke motors. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.