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2003 rm125 powerband?

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Hi

I recently bought my first dirtbike and im having some issues with it? It doesnt feel like its hitting powerband! It revs and screams but no power. i rode my friends kx100 ad dropped the cluth on 3rd and it popped a wheelie but this fu@##g rm won even do it in first. it feels like it boggs down in the low end too! Does anyone have any suggestions? im very new to bikes so if you have any suggestions it would help if you explained it a little more thoroughly.

Thanks

pics of it

http://s1219.photobucket.com/albums/dd433/maks630/

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Hi

I recently bought my first dirtbike and im having some issues with it? It doesnt feel like its hitting powerband! It revs and screams but no power. i rode my friends kx100 ad dropped the cluth on 3rd and it popped a wheelie but this fu@##g rm won even do it in first. it feels like it boggs down in the low end too! Does anyone have any suggestions? im very new to bikes so if you have any suggestions it would help if you explained it a little more thoroughly.

Thanks

pics of it

http://s1219.photobucket.com/albums/dd433/maks630/

It most likely needs a freshing up, like piston/rings/wrist-pin/bearing ect.

It would be very advisable since the bike was bought used, also check the air-filter and the intake tract for dirt.

The aluminum covers on the cylinder are the powervalve covers, I would suggest purchasing an shop manual.

They are very thorough and would help you get started.

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Maybe sell it and get another 125, I've heard good things about the yz125 so maybe have a look at one

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im almost positive its something retarted like the pistons backwards or sumthin dumb like that...Im not gonna sell it because of a little problem.

How would i go about checking if the powervalve is stuck? could that be the problem?

Edited by maks630

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How does the plug look? Maybe needs re jetting? Maybe linkage on power valve not connected? Read through manual and go over bike, hands on is the best way to learn. Also check out the jetting sticky at top of forum to help if it needs jetting.

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I had the exact same problem as you! Except on a KTM 105 SX. The thing would rev and scream but just never put any power down and it went through the gears like instantly. I put a new top end, new silencer and nothing. I went through the powervavle and wouldn't you know it! The spring that actuates the powervalve was on backwards. :smirk:

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did you just take off the right side cover on the cylinder or did you take aprt the whole thing in thje front?

thanks

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It was just a cover on the right side of the cylinder for the 105. Not sure about RM 125 though.

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What exactly should i look for under that cover? When i rev the bike up should anything in there move? Srry for dumb questions its my first bike. Thanks

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I don't think the powervalve should be open when you have the bike running. Correct me if I'm wrong but just look to make sure it's actually actuating when you pull on it and that it actually has some resistance.

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just went thru my 99 rm125, so should be very similar.

on right side of cylinder is the cover (pv rod) take cover off and see if you can manually move the pv should move with relativly little pressure. if it moves you can start the bike up and run thru the rpm and watch it open .

If it is not opening either the actuater gear is busted or the valve spring is set to tight.

The manual should have the proper procedure for setting the spring tension

if its a busted gear thats a whole set of other problems.

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I just pulled the schematics for your bike.

03 had non adjustable spring.

There are two small bolts that hold the actuator arms onto the rod (inside the front cover). If someone left them out or they have broken somehow all the parts could be moving except for the pv themselves.

If the rod on the right side is moving when you rev the bike you will need to take the front cover off to see if the pv's are actually moving. Getting this cover off in the frame will probably be difficult.

What you are describing sounds a bit off. if the powervalves were stuck shut you would have good power down bottom but nothing up top. All the power valves do is stretch the powerband into the lower rpms and soften the hit when you get into it, then get out of the way up top. Riders have taken them completely out on older models and the usually result is its a dog down loww but then when it hits the powerband its all on.

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does the jetting really affect the power that much?? just curious?

Jetting makes all the difference in the world. But a bike with a bad top end will not jet correctly.

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Im goin riding this weekend so i willl pull taht cover off to see if it opens up. Just a simple question. To remove the cover i have to remove the pipe. Can i run the bike with the pipe off. I know this is probably a really dumb question but i just want to make sure i wont screw anythin up. BTW the guy i bought it from never even said one word about jetting so that will probably be the next thing i check if its not the pv. Can anyone tell me what the jetting should be? We ride in Jersey state forest not sure on the altitude and stuff but temp should be 70-85 outside when we go.

Thank You so much for all the help you guys

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PV concerns are valid. However: after reading the OP's description, I am inclined to think the clutch is either not "brand new" (Some people don't tell the truth!?! I'm shocked!) or the clutch cable is way out of adjustment. His description indicates a slipping clutch, at least to me (he said it revs up but doesn't do anything).

Here's how to adjust it: Loosen the locknut where the clutch cable and lever connect. Loosen the barrel adjuster until you can slide a nickel between the clutch lever and the clutch perch. Tighten the locknut. Test it out.

This is an important adjustment and maybe not caught by a first-timer. If the clutch has no free play, it will slip, causing in a big loss of power to the ground.

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should i leave the perch and the clutch loose tho? Im just thinking it may be pretty wabbaly? And also when i tighten up the lock nut should i tighten it all the way in or 3/4?

Thanks for the tip...I will try that b4 taking offf thee cover...do you know if i can run the bike without a pipe tho?

Thanks

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There should be about 1/16 inch between the clutch lever and the perch. The lever will wobble a little if it's worn. I wouldn't run the motor without the pipe. It would be REALLY loud and it will not want to keep running. If you remove the side cover and try to move the power valve by hand, and the rod is connected, it should be ok. There will be more resistance the farther you try to turn it. If it's turns smooth,it should be ok.

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If it's reving and screaming but not going anywhere fast I'd say your clutch is the issue.

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