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2001 RM 250 loud ping 1/8 throttle??? with a hit

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Whats up guys! A little back story to start here. Picked up an 01 RM 250 about 5yrs back for $600 excellent shape! Black Excel rims, Pro-circuit platinum Pipe and  R304 Shorty, it was a good deal from a neighbor not a stolen bike. Ran it for about 3yrs once a month all day trail rides and a little mx track mixed in. The bike has always been finicky as hell and could throw back then all 220lbs of me on my a$$ now I've gained a daughter and a few lbs! Ok back to the back story! So about 2yrs ago bike basically one day started up within a few seconds absolutely sounded like I grabbed a handful of nuts as bolts and through it into the cylinder turned her off and well money was tight so she sat until about a month ago. Rebuilt the motor from crankcase up! Found that the V-Force 2 reed cage had decided one of its tiny screws that hold it together wanted to suck into the motor and jump around and piss off all my fun. Here I am now fully rebuilt and have an issue that even before was an issue and why this bike always scared the $hit outta me! The hit on this thing is unforgiving even at low 1/8 twist of the throttle. Now I have been looking into all the reading and can't find my answer. The thing is this bike will sound good on the pipe but last night doing a test ride down the street maybe 1st gear 1/8-1/4 throttle around that position the bike goes from normal dirt bike sound to this high pitch pinging like the REEDS are pissed off and want to be heard over the exhaust and at the same time it feels like its in a powerband pull. Its not just me I've had guys who ride semi pro get on my bike and can't maintain enough throttle control to wheelie the bike everyone ends up on their A$$. My thoughts are detonation issues/Powervalve adjustment/carb issues? I really need some advice between rebuilding this thing and re-doing the suspension to fit my dad bod I'd like a bike that may have a little in between not all or nothing!

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34 minutes ago, szextreme said:

Whats up guys! A little back story to start here. Picked up an 01 RM 250 about 5yrs back for $600 excellent shape! Black Excel rims, Pro-circuit platinum Pipe and  R304 Shorty, it was a good deal from a neighbor not a stolen bike. Ran it for about 3yrs once a month all day trail rides and a little mx track mixed in. The bike has always been finicky as hell and could throw back then all 220lbs of me on my a$$ now I've gained a daughter and a few lbs! Ok back to the back story! So about 2yrs ago bike basically one day started up within a few seconds absolutely sounded like I grabbed a handful of nuts as bolts and through it into the cylinder turned her off and well money was tight so she sat until about a month ago. Rebuilt the motor from crankcase up! Found that the V-Force 2 reed cage had decided one of its tiny screws that hold it together wanted to suck into the motor and jump around and piss off all my fun. Here I am now fully rebuilt and have an issue that even before was an issue and why this bike always scared the $hit outta me! The hit on this thing is unforgiving even at low 1/8 twist of the throttle. Now I have been looking into all the reading and can't find my answer. The thing is this bike will sound good on the pipe but last night doing a test ride down the street maybe 1st gear 1/8-1/4 throttle around that position the bike goes from normal dirt bike sound to this high pitch pinging like the REEDS are pissed off and want to be heard over the exhaust and at the same time it feels like its in a powerband pull. Its not just me I've had guys who ride semi pro get on my bike and can't maintain enough throttle control to wheelie the bike everyone ends up on their A$$. My thoughts are detonation issues/Powervalve adjustment/carb issues? I really need some advice between rebuilding this thing and re-doing the suspension to fit my dad bod I'd like a bike that may have a little in between not all or nothing!

Curious is the power valve is stuck open?

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Power valve is my first thought too. The ‘00 & ‘01 RM 250’s had a Power valve solenoid that plugs up, and a lot of guys just remove them since they cost $100 to replace. The “band aid” fix if solenoid has been removed is to tighten up the PV adjustment from 1/2 to 1 full turn. 

Another thing is your reeds. Are you still using V Force? Those things are known for not sealing well. At low RPM they leak A/F back through the carb requiring a leaner air screw adjustment. Then, when RPMs get high enough they slap down hard enough to seal, and everything 1/8 throttle and below goes lean...

Go back to stock with Boyesen reeds, or go with Boyesen RAD valve... V Force is only good for high RPM racing...

Edited by Jeremyf1
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1 hour ago, Jeremyf1 said:

Power valve is my first thought too. The ‘00 & ‘01 RM 250’s had a Power valve solenoid that plugs up, and a lot of guys just remove them since they cost $100 to replace. The “band aid” fix if solenoid has been removed is to tighten up the PV adjustment from 1/2 to 1 full turn. 

Another thing is your reeds. Are you still using V Force? Those things are known for not sealing well. At low RPM they leak A/F back through the carb requiring a leaner air screw adjustment. Then, when RPMs get high enough they slap down hard enough to seal, and everything 1/8 throttle and below goes lean...

Go back to stock with Boyesen reeds, or go with Boyesen RAD valve... V Force is only good for high RPM racing...

My 2004 had RM125 (had some Boyseen resin reeds (I ordered the metal reed stops) - and the Boyseen Fiber Reeds (runs perfect). I used a Rad Valve in the past on some KX's but has been some years.

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I’ve found the RAD valves make the biggest difference in the pre ‘00 bikes. More modern bikes have much better shape inside for good airflow. 

Figured if he has to buy a stock reedcage and new reeds, the RAD valve might not cost much more, and comes with reeds ready to go.... I’m sure his stock carb boot has already been chopped on for the V Force too. 

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Think I may have it sorted out! Went back took the power valve spring out on the left side of the jug and put it to 1/4 clockwise turn. Got the book out and adjusted the carb to stock since its been awhile. Runs 100% better but still trying to figure out I have the idle screw within a half a turn of completely shut and still having a little bit of break up when rolling into the throttle any suggestions with that? My Jetting is exactly what pro-circuit recommends for their pipe on an 01. I do have a JD jetting kit but kind of reluctant to put it in as the first part of the instructions say move the needle to the 4th clip WTF?

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