Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: jdb1282 on September 05, 2012, 06:46:45 AM

Title: 2008 RM250 hole small hole in exhaust
Post by: jdb1282 on September 05, 2012, 06:46:45 AM
there is a hole at the bottom weld point where the fmf logo used to be since it got ripped off, its about half the size of a button on a button up shirt will this make a noticeable difference in engine performance or not much. engine feels like it falls off to fast like it should have a little more in upper rpm of powerband, im expecting more but it just acts like its over revved. i know this RM has shorter stroke compared to yamaha could that be it or maybe the hole in pipe.
Title: 2008 RM250 hole small hole in exhaust
Post by: TMKIWI on September 05, 2012, 09:24:40 AM
I would get the hole fixed anyway.
Nothing wrong with the power of the RM's.
Title: 2008 RM250 hole small hole in exhaust
Post by: cnrcpla on September 05, 2012, 12:38:05 PM
Yeah, X2, get the pipe fixed anyways even if it isn't causing any trouble.
Title: 2008 RM250 hole small hole in exhaust
Post by: SachsGS on September 05, 2012, 03:22:10 PM
Weld er up. The noise would drive me crazy. ;D
Title: 2008 RM250 hole small hole in exhaust
Post by: jdb1282 on September 06, 2012, 04:10:34 AM
so it shouldnt make a diference, im going to get new gnarly or fatty or try welding. it does sound alot different than all the other 2strokes on the track sounds like an old school 2stroke
Title: 2008 RM250 hole small hole in exhaust
Post by: _X_ on September 07, 2012, 12:46:11 AM
no it sounds like there is a hole in the pipe. HA!
Title: 2008 RM250 hole small hole in exhaust
Post by: jdb1282 on September 07, 2012, 04:00:20 AM
anybody have any idea why it cuts out early like im over revving to early? only thing i can figure is the exhaust valve may not be opening enough, oh also how many ounces for a 40:1 premix ratio in 1 gallon can with yamalube no info on the bottle?
Title: 2008 RM250 hole small hole in exhaust
Post by: cnrcpla on September 07, 2012, 04:44:18 AM
3.2 ounces to be exact for 1 gallon of gas to mix 40:1. And maybe the clutch is slipping causing you to think its revving out faster than it should. I just had that issue with my 250, turns out the cable had to much tension on it because I hadn't checked it in a while. Check your cable, and maybe change the tranny fluid, and checking the PV wouldn't hurt either.
Title: 2008 RM250 hole small hole in exhaust
Post by: rmpilot on September 08, 2012, 10:39:08 PM
Quote from: jdb1282 on September 07, 2012, 11:00:20 AM
anybody have any idea why it cuts out early like im over revving to early? only thing i can figure is the exhaust valve may not be opening enough, oh also how many ounces for a 40:1 premix ratio in 1 gallon can with yamalube no info on the bottle?

I would assume the hole is making the ehaust system act like its shorter which shortens the breadth of power and quickens the reving of the engine just like a shorty silencer.
Title: 2008 RM250 hole small hole in exhaust
Post by: Tcinutoo on September 10, 2012, 03:06:17 PM
FMF pips do feel that way on 07/08 model, Put on the pro circuit or a bills for more top end with a shorty , The stock pipe will do better then fmf