02 cr250 power valve not opening

So I just bought an 02 cr250 and it kicks fine, idles great and everything, but wont open up when revving or riding. You can see when revving it, the RC valve isnt opening the powervalve. I have checked the RC motor by applying 12vdc to both the open and closed side, both operate normally and when idling the valve stays closed just fine. The cables are adjusted properly. I looked at all my wires and they look fine, I am not sure where else to go here. Any help would be greatly appreciated. Thank you.

So I just bought an 02 cr250 and it kicks fine, idles great and everything, but wont open up when revving or riding. You can see when revving it, the RC valve isnt opening the powervalve. I have checked the RC motor by applying 12vdc to both the open and closed side, both operate normally and when idling the valve stays closed just fine. The cables are adjusted properly. I looked at all my wires and they look fine, I am not sure where else to go here. Any help would be greatly appreciated. Thank you.

You should go to the honda 2 stroke forum and post this.  They will fix you right up.  Mine did the same and I needed a new electric motor.  Sounds like it might just be carbon buildup though.  Does it turn by hand?

So I just bought an 02 cr250 and it kicks fine, idles great and everything, but wont open up when revving or riding. You can see when revving it, the RC valve isnt opening the powervalve. I have checked the RC motor by applying 12vdc to both the open and closed side, both operate normally and when idling the valve stays closed just fine. The cables are adjusted properly. I looked at all my wires and they look fine, I am not sure where else to go here. Any help would be greatly appreciated. Thank you.

 

So I just bought an 02 cr250 and it kicks fine, idles great and everything, but wont open up when revving or riding. You can see when revving it, the RC valve isnt opening the powervalve. I have checked the RC motor by applying 12vdc to both the open and closed side, both operate normally and when idling the valve stays closed just fine. The cables are adjusted properly. I looked at all my wires and they look fine, I am not sure where else to go here. Any help would be greatly appreciated. Thank you.

I have read theads on this..i have a 86 cr250 r and trying to use a 89 cylinder..and i think i am gonna have to swap valves over...but on alot of threads i read alot of problems with those are one of two things...your valves have carbon built up on them..take it apart and clean with karosine...2 the spindle cam may be damaged...make sure the spindle cam follower is connected at the bottom where the water pump is on the crank case...that might be the problem as well...i have also read if you take the cylinder off...the valves should be wide open..and when installing it should be pushe into the closed position to put it back on..it will drop into place as your closing it..thats my best advice...first make sure the spindle cam follower is connected then go from there with the karosine cleaning

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So I just bought an 02 cr250 and it kicks fine, idles great and everything, but wont open up when revving or riding. You can see when revving it, the RC valve isnt opening the powervalve. I have checked the RC motor by applying 12vdc to both the open and closed side, both operate normally and when idling the valve stays closed just fine. The cables are adjusted properly. I looked at all my wires and they look fine, I am not sure where else to go here. Any help would be greatly appreciated. Thank you.

mine was acting the same, check the actual servo motor I bet it its corroded and rusted bad like mine was water had got in it from washing the bike frequently. A new servo motor is $4.99 at RadioShack or a hobby shop and fixed my problem which sounds like yours for 5$ it's worth a try. If that doesn't work test all the wires with a Meter.

First off an 80's cr250 has a totally different power valve system then an 02, but you are right on one thing and that is that the valves can get gummed up with carbon. Start by taking off the rc valve cover and try to turn the butterfly by hand. Full clockwise is closed and full counter clockwise is open. There is going to be some resistance from the cables but it should turn by hand. If not then either the cables are not adjusted properly or the problem lies within the cylinder (possibly gummed up). If everything spins fine then start the bike while the cover is off and inspect that the butterfly turns fully open when you give it throttle. If it simply doesn't not move at all then it is most likely electrical and if it moves a little bit then it can either be the cables or electrical. To determine the electrical side of things you need a multimeter. The cdi controls the servo motor so either of those two parts can be at fault and testing each one is the only way to find the problem aside from throwing parts at it. As mentioned already you can buy a new motor from a hobby shop or online for much cheaper than what Honda sells them.

I can't get mine out! Disassemble everything and nothing it rattles around but won't come out I've used carb clean degreaser soaked er over night ..scratched ..idk maybe hit it with a pressure washer any ideas?

What exactly can't you get out? What year and model is your bike?

Thanks for all the replys, Ive checked the motor by applying 12 volts and swapping polarity like the manual says, it checks good. The valve moves freely and everything. When i have the valve cover off and the engine running, it immediatly snaps to the closed position like its supposed to and when revved it does not open at all. I measured voltage to the motor while the engine is running and it gets about 2-3 volts to the closed side, never going negative like it should be for closed.. I took the whole wire harness off and hoped for a broken wire somewhere and found nothing.    I am at the point where it could only be the CDI I think. Unless the CDI is getting funky voltage in..Im not really sure what is supposed to be going in. I will work on it more tomorow and let you all know.  Does anyone know by change how to meter the CDI and verify that its busted? Thanks again for the help..

why guess...check the wire harness over for continuity with a multi-meter. its easy to do..just takes a few beers.

 

after that start checking resistance in all other parts. sounds liek the servo is shot IMO

All the wires check good, the only thing I cant test is the ECM (CDI) so I jus bought a used one from ebay for 65 bucks. The honda shop wanted 220 for a new one, no thanks. Choppertown, why would you say it sounds like the servo if the servo actuates when 12vdc is applied?

All the wires check good, the only thing I cant test is the ECM (CDI) so I jus bought a used one from ebay for 65 bucks. The honda shop wanted 220 for a new one, no thanks. Choppertown, why would you say it sounds like the servo if the servo actuates when 12vdc is applied?

mine turned both ways with a 12v battery hooked up too but the motor was shot

Ok well i was still only getting like 3 volts to the open side and 0 volts to the open side. The CDI is on its way, ill let yall know whats upm when I get it

Ok well i was still only getting like 3 volts to the open side and 0 volts to the open side. The CDI is on its way, ill let yall know whats upm when I get it

if the CDI doesn't do anything check your servo motor for rust. Luckily if its a servo motor it's a cheap fix. A new one that is the exact same only looks a little tougher than the one Honda put in there is $4.99 at a RadioShack or hobby shops.

if the CDI doesn't do anything check your servo motor for rust. Luckily if its a servo motor it's a cheap fix. A new one that is the exact same only looks a little tougher than the one Honda put in there is $4.99 at a RadioShack or hobby shops.

I will definatly do that. Thanks.

Well, it wasnt the CDI..tomorow ill try a motor...

I had to take mine out through the piston side whe it was gummed up. You have to turn and pull on it it comes out at a angle. Hooe this helps. When the valves and cylinder is clean it should come out relatively easy.

Ok, so i bought the electric motor from radio shack. How do I get the little gear off the old one to put on the new one? This thing seems stuck on there.

Ok, so i bought the electric motor from radio shack. How do I get the little gear off the old one to put on the new one? This thing seems stuck on there.

just heat it gently with a torch and put it in a vice (motor with the shaft sticking up) and use pliers and put them below the gear and pull up and it should slide off like mine did then when you put it back on use the red lock tight on it and make sure it's in the right place and leave it for awhile.

Alright. Thanks, ill try that...i just went all around my city and nobody has a gear puller that small...A hobby shop had one but it broke years ago lol..HEAT IT IS! God I hope this fixes my problem..which Im thinkin that since i never even got the voltage to the motor for opening the power valve that this wont fix it, but who knows...worth a try..only 6 dollars at radio shack.

Alright. Thanks, ill try that...i just went all around my city and nobody has a gear puller that small...A hobby shop had one but it broke years ago lol..HEAT IT IS! God I hope this fixes my problem..which Im thinkin that since i never even got the voltage to the motor for opening the power valve that this wont fix it, but who knows...worth a try..only 6 dollars at radio shack.

just be easy on the pinion gear it'll squish like butter if u grab onto it with pliers haha saw someone do that. I think that'll fix your power valve problems then try to get the jetting sorted out one day the mikunis rich then pinging!

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