Hp of a 2003 yz125 with fmf rev and prosercit shorty

Lack of power is usually bad valves. Clean the air cleaner and do a compression check. Could you take a moment and rate my answer? Thanks!

if you have any friends that weld. ive had this problem myself and have found it cheaper and less stressful to fabricate yourself than to search any further

change the jetting...youcan contact FMF for thier setup recommendations for running that pipe with the bike...very common problem and jetting will take care of alot of the issue

I have an 04 125 with a FMF fatty Factroy expansion chamber and a Titanium 2 FMF silencer (shorty) the carb settings are Pilot a size leaner than stock main IS stock jet needle is a setting toward lean and air screw is two turns out. My gas:oil mix is around 32:1 - 40:1.. My spark plug buget is killing me, and I havemessed with it til I was blue in the face can anyone help me?,don't worry I didn't take it wrong it is a good question, and let me put it this way.. I run it like a two stroke lol I have had more than my share of two strokes so I don't lolly gag it and usually for the trails I ride you really can't get out of 1st most of the timeI spend most my time around 3/4 throttle. When I 1st got the bike I had a friend messing with the idle screw on it cause it wouldn't idle at all and he messed with the mix screw by accident so I think it was screwed out more than two turns but I set it according to FMF recommendations with the pipe and chamber. The guy who had it before me raced it in a AMA class I don't know which so don't ask lol, so who knows what has been done to it other than what I can see,,,

I have an 04 125 with a FMF fatty Factroy expansion chamber and a Titanium 2 FMF silencer (shorty) the carb settings are Pilot a size leaner than stock main IS stock jet needle is a setting toward lean and air screw is two turns out. My gas:oil mix is around 32:1 - 40:1.. My spark plug buget is killing me, and I havemessed with it til I was blue in the face can anyone help me?,don't worry I didn't take it wrong it is a good question, and let me put it this way.. I run it like a two stroke lol I have had more than my share of two strokes so I don't lolly gag it and usually for the trails I ride you really can't get out of 1st most of the timeI spend most my time around 3/4 throttle. When I 1st got the bike I had a friend messing with the idle screw on it cause it wouldn't idle at all and he messed with the mix screw by accident so I think it was screwed out more than two turns but I set it according to FMF recommendations with the pipe and chamber. The guy who had it before me raced it in a AMA class I don't know which so don't ask lol, so who knows what has been done to it other than what I can see,,,

I have an 04 125 with a FMF fatty Factroy expansion chamber and a Titanium 2 FMF silencer (shorty) the carb settings are Pilot a size leaner than stock main IS stock jet needle is a setting toward lean and air screw is two turns out. My gas:oil mix is around 32:1 - 40:1.. My spark plug buget is killing me, and I havemessed with it til I was blue in the face can anyone help me?,don't worry I didn't take it wrong it is a good question, and let me put it this way.. I run it like a two stroke lol I have had more than my share of two strokes so I don't lolly gag it and usually for the trails I ride you really can't get out of 1st most of the timeI spend most my time around 3/4 throttle. When I 1st got the bike I had a friend messing with the idle screw on it cause it wouldn't idle at all and he messed with the mix screw by accident so I think it was screwed out more than two turns but I set it according to FMF recommendations with the pipe and chamber. The guy who had it before me raced it in a AMA class I don't know which so don't ask lol, so who knows what has been done to it other than what I can see,,,

I know there were a few different models: X440S only FMF Powercore aluminum silencer/stainless header combo E440/C440 standard header/silencer with midpipe attached (long can) (2 spark arrestors) S440 standard header/shorty silencer with seperate midpipe (1 spark arrestor) X440 standard header/silencer (NO spark arrestors) Just wondering whether anyone has ever done any hp tests between these. From my experience the X440 can would flow the best because of the lack of spark arrestors but I'm wondering how the FMF powercore compares? The FMF has shorter header runners leading to the merged portion so the shorter header should deliver more low end torque. Also do I have the S440 can info right, only 1 spark arrestor in the shorty?,The so-called S440 pipe did not have a separate midpipe. It had a fixed welded inlet, same as the longer can, and was full open. Also, I have a New 03 X440 here with the SAME exhaust, ...but another with a long and full-open version. So, you really cannot tie all exhaust versions to a particular model, since too many owners will get confused. Everybody would need to check their own machine to be sure. But if ANYBODY out there has a separate midpipe?, I'd really like to confirm wazzup -- Up until now, I have thought that the only ones around are from the small batch that I had found over in Holland. And, on just a few bikes that were assembled in Europe just prior to the bankruptcy. ,,,