Dirt Rider Magazine

Ryan

hey guys, i recently got a 1998 rm 125 with a keihin 36mm carb. my question is, it bogs when im in mid-high rpms. but if i flick the throttle real quick it'll rev pass this bog spot. i already cleaned the carb and this is still happening, I'm assuming its the floats in the carb or i need a top end. i checked the compression and its 130psi on a cold cylinder WOT. I'm running 30:1 with AMS oil.

Any ideas? Thank you!

Ryan

since its sub 30degrees out could it be running to rich?

turbowagonman

Is a 2 stroke they don't make the power untill the bike is in a higher rpm/a more narrow power band

Ryan

i know that, im saying its bogging mid-high rpms, and it gets stuck there.

edubldee

have you ridden it hard after getting it past the 'bog spot'? does it stop doing it briefly if you have? Is your spark plug fouled? powervalve sticking? 30:1 is quite a rich mixture, id check/change the plug first then if no change try a leaner fuel mixture/ lean the settings out on the carb slightly an take it from there. theres quite a few things which could make this happen, try the easiest first. does it feel like its stuttering? or is it just no power at that spot?

NZrider

is this model equipped with an electronic power jet? if those fail it can cause a lean bog in the midrange i believe

Ryan

if i flick the throttle, it will go pass this "bog spot". but if i flick it again it will still bog. my spark plug is slightly wet. only on one side. I'm not sure if the power valve is sticking. There's just zero power at that particular spot. I can't use the bike to its full potential since it just bogs there 90% of the time. and

this model is not equipped with an electronic power jet.

Ryan

i leaned it out a bit with the air screw. runs good now.

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