yz 125 stutter

[Butcher-Boy]

99 yz 125,fmf fatty pipe, shorty silencer, v-force reeds, otherwise stock. I got this bike a while back and as far as I'm told the former owner raised the needle one position from stock to try and cure plug fouling. The bike still fouls plugs from time to time but my main gripe is it stutters a little as the powerband is comming on. It's not real bad but it is getting quit annoying during trail rides. It idles fine and has plenty of power on top. I did try a search but only came to the conclusion that these are wierd carbs so I thought I would post to see if anyone has had similer problems. Oh and if it helps i'm at 850' elevation and run 92 pump gas with yamalube 2r. Thank you for your time.

 

[Butcher-Boy]

Mixed at 32:1 also

 

[heinousberzerker]

my YZ used to do that, this might sound too obvious, but try cleaning the air filter thoroughly with simple green or dish soap, dry thoroughly, oil the filter and put it back on. if it still stutters and isn't crisp throughout the throttle range, run it sitting on the stand without an air filter (as long as it isn't windy and dusty, it's a good idea to cover the airbox holes with clean cloth while doing this, and if it sounds great, you probably need a new air filter. also try cleaning your in-tank fuel filter. another thing that helped me is repacking my silencer and soaking my pipe in diesel overnight and then swishing the diesel around inside the pipe as hard as I could before dumping it out (you have to plug both ends). you wouldn't believe how nasty that diesel was, it was like black soup. my bike never fouls plugs tho, that is in the carb more than likely.

 

[robwbright]

You might wanna take a look at this

http://justkdx.dirtrider.net/carbtuning.html

 

[Butcher-Boy]

Thank you gentelman for the reply, both were taken into consideration and checked out. I'm not much of a carb guy, In fact I hate carbs and I always seem to screw things up worse then they were before. I'm going to start a new topic on something I did find that may be wrong and might have something to do with the problem. Is there suppose to be A gasket inbetween the reedcage and the engine?