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cr250 no power please help

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hi there everyone i have just bought a cr250 1996 and it is very very slow

i have also got a rm85 04 model and that murders the 250 in a race.

my mates got a kx250 2000 model and that wheelies through the gears and tears up mud my cr250 you can pull on it and it wont wheelie at all.

my bottom end is shockingly lacking power

through 1st 2nd its bogging a little and clears up a bit in 3rd but still doesnt

really go anywhere can anybody help me fix this problem replys much appreciated thanks for any help.

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i used to have a 96..they will scream when running right. When was the last time top end was changed? Jetted correctly? Sure clutch aint slipping?

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I can help.

first of all, you need to find out if the thing has any compression. Borrow a guage and screw it intothe spark plug hole and crank it. If it's not making 100 psi you need to re ring it.

secondly, make sure the powervalve is operating, remove the large hex cover on the lh side of the cylinder and start the bike, rev it and see if the valve rotates to the open position, if not it is either gummed up or something mechanically wrong with the linkage.

The other things that need to be checked is the

1. reed valve, make sure it is staying closed, ( no gaps )

2. ignition timing, make sure the timing marks are lined up

3. jetting, take a good look at the spark plug, it should be lite brown on the electrode.

4. Ehhaust pipe, Pull it off and make sure the carbon is not built up too much to cause a restriction.

if anything else let me know, my 2001 is a rocket and they are the same engine.

Al

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Is the plug clean, or fouled? Maybe try a new one and check the plug wire's integrity. Jetting? Power valve? There are many places to look you just have to start looking and fixing problems as they as you find them. That bike was fast in '96 and should still be fairly quick now. Good luck and let us know how it is going. RB

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i havent had chance to check owt yet i got really depressed after my ride ahaa but when i came back from a ride the exhaust was smoking for a while and it smelt horrible abit like a bad bbq the smoke was clear white

and thanks for the help guys

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i compared my bike by kicking the kx250 and kicking mine and me and all my mates said mine had more compression

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Lots of things to check... Have you looked at the spark plug? Have you done a compression test?

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Check your powervalve and make sure it is working properly. Might not hurt to check your reeds, clean your carb thoroughly, clean/replace jets, and make sure it is jetted properly.

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Check with a compression gauge to make sure. Then swap in a new plug, check ALL of the intake/exhaust components to make sure that everything is flowing, give the carb a thorough cleaning, and make sure you're pre-mixing your gas :smirk:

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when it is running ok will it wheelie through the gears like my rm used to do and thanks ill be checking everything tomorrow your help is much appreciated

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thanks for the help il be checking everything tmora and will get back to you and does anyone now what they are supposed to be jetted at

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Depends on your mix ratio, climate, elevation, and the type of riding you do.

Stock jetting is:

#175 main

#55 pilot

1370 needle 3rd position

air screw 2 turns out.

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Sounds a lot like what my son was saying about his bike before we replaced the Whole bottom end...

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make sure the powervalve is operating :smirk:

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I can help.

first of all, you need to find out if the thing has any compression. Borrow a guage and screw it intothe spark plug hole and crank it. If it's not making 100 psi you need to re ring it.

secondly, make sure the powervalve is operating, remove the large hex cover on the lh side of the cylinder and start the bike, rev it and see if the valve rotates to the open position, if not it is either gummed up or something mechanically wrong with the linkage.

The other things that need to be checked is the

1. reed valve, make sure it is staying closed, ( no gaps )

2. ignition timing, make sure the timing marks are lined up

3. jetting, take a good look at the spark plug, it should be lite brown on the electrode.

4. Ehhaust pipe, Pull it off and make sure the carbon is not built up too much to cause a restriction.

if anything else let me know, my 2001 is a rocket and they are the same engine.

Al

This,

Start by doing all this then come back if it's still not running right. My gut feeling says it's the muffler though. But could be the head gasket because of the white smoke.

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today i took off the power valve nut on the left hand side which is a 17mm nut and and it is pointing on H ive heard its meant to move when i full throttle it could this be the reason why it is not going fast thanks for any help

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