Messages

1

Technical / How much porting do you really need to do it you bore your cylinder over?

« on: May 06, 2013, 04:17:07 AM »

The rod lengths are not the same.

Definitely not a simple bolt on.  Still doesn't answer my question about porting after you bore oversize.

Why wouldn't it be a straight swap? the crank cases are the same!

The answer to your question is that there is no point doing either (porting or boring) to an early RM125 engine because you can get far better gains from installing the newer style RM motor.

2

Technical / How much porting do you really need to do it you bore your cylinder over?

« on: May 02, 2013, 12:30:26 AM »

Definitely not a simple bolt on.  Still doesn't answer my question about porting after you bore oversize.

3

Technical / How much porting do you really need to do it you bore your cylinder over?

« on: May 01, 2013, 05:00:54 AM »

Why do you say +05?

4

Technical / How much porting do you really need to do it you bore your cylinder over?

« on: April 30, 2013, 03:55:30 AM »

I picked up a 2001 RM 125 and the cylinder has some scoring.  I'm debating about doing a 144 kit, but I keep having to remind myself that it's a 2001 and I will never get back out what I sink into it.   I can just repair the cylinder but for slightly more I can have them bore it to a 134 or 144.   I heard from an engine builder that most of the modern 125's come pretty good from the factory and even if you bore them oversize there isn't too much in terms of port timing needed.  Yes you can get more power by porting but most of it would come from the boring i.e. you don't really need to port it.  So does anyone have concrete knowledge on how good/bad of an idea is is to do a big bore without porting?