RM250 Is low compression a cause of bogging at certain rpms?

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Lineman353

Hi everyone, I am new to this forum. I was wondering if anyone is able to tell me whether low compression can cause bogging at certain rpms? I have a 01 rm250. I have jetted the bike so many times and currently running stock (stock pipes). Compression at the beginning of last season was about 172-175. As the season neared the end I noticed loss of power at certain rpms. Good top end speed. Bike also smelled a little like burning at the end of a ride (at exhaust silencer). I also just replaced the silencer pack as it was way over due. I am going to do a new top end before the start of this season. Looking for any other suggestions for my bogging. Thanks for your help.
 
2strokesteve89

2strokesteve89

Lineman353:
Hi everyone, I am new to this forum. I was wondering if anyone is able to tell me whether low compression can cause bogging at certain rpms? I have a 01 rm250. I have jetted the bike so many times and currently running stock (stock pipes). Compression at the beginning of last season was about 172-175. As the season neared the end I noticed loss of power at certain rpms. Good top end speed. Bike also smelled a little like burning at the end of a ride (at exhaust silencer). I also just replaced the silencer pack as it was way over due. I am going to do a new top end before the start of this season. Looking for any other suggestions for my bogging. Thanks for your help.
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where exactly is it bogging? just off idle, mid range? could be an air screw or needle adjustment. check the compression now or at least before you tear it down again. always good to have a base line to work with. is the power valve working? maybe it has carbon buildup to the point up that it isn't functioning properly.
 
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Lineman353

2strokesteve89:
where exactly is it bogging? just off idle, mid range? could be an air screw or needle adjustment. check the compression now or at least before you tear it down again. always good to have a base line to work with. is the power valve working? maybe it has carbon buildup to the point up that it isn't functioning properly.
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I'm not sure if this engine has a power valve. I can't find anything in the manual about a power valve. It bogges midrange. Everything on the bike is stock including air screw and needle placement. Thanks for suggesting another compression test before rebuild.
 
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ossagp

you mention that you have been changing lots of jets, but no mention of why. you dont mention resetting your float level to factory specs though. many times when you have to chase jetting around like that it is due to the float setting being off and or the float needle being worn or that little spring in it gets weak. I do believe your are about to need a piston and rings though. cleaning the powervalves is part of doing the top end for most of us.
 
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Lineman353

ossagp:
you mention that you have been changing lots of jets, but no mention of why. you dont mention resetting your float level to factory specs though. many times when you have to chase jetting around like that it is due to the float setting being off and or the float needle being worn or that little spring in it gets weak. I do believe your are about to need a piston and rings though. cleaning the powervalves is part of doing the top end for most of us.
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Thanks, I have been changing jets due to my mid range bog. It is all back to stock now. I am doing the top end and I will look I to the float at the same time. Thanks for the suggestions.
 
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