Motor Help Needed Please:(

hello everyone, as some of you may know i recently bought a 1999 WR400 and spent the past few weeks getting her back to running condition. anyway we got the bike all back together on Saturday and it ran great. started first kick every time. but we noticed the decompression lever thats on the motor with th spring wasn't springing back. we realized the spring had spun around so we very carefully removed the bolt holding it in and pulled the little assembly out, put the spring back where it was supposed to be and after what seemed like forever of spinning it back and forth we finally got it back in and installed the little bolt very carefully. then we tried it out and it worked like a charm. it sprung back and the motor started with ease multiple times and sounded great. then i decided since it stopped raining i was gunna take the bike out Sunday. i got all my gear on and spun the kick start till i got her to TDC and pulled the decompression lever and nothing. the lever on the motor was moving and springing back but was not letting me move the kick start at all. and after reading some stories on here i didn't try and force it because i didn't want to split the case. i had no clue *** happened, she had full oil, and coolant which we had just put in the day before and it ran like a dream. i thought maybe she seized but we checked all the oil lines and filters and there was no blockages so theres no way it starved itself of oil. so we removed the spark plug and took the little circular side cover out on the left of the motor and cranked her over manually and it wasn't seized at all. it felt like a motor normally would. so i tried the kick start again and it was moving again and i thought YES! so i started cranking it with the kick start but once i get to TDC it stops like normal but once again the decompression lever does nothing. but i can still crank it over manually on the left with a ratchet. once its past TDC the kick start works and i can crank it over till it gets to TDC then it stops again and decomp lever doesnt let it decompress. im sorry for such a long post but i really need help. is there anything we did wrong when we removed the decompression arm from the motor? im taking any suggestions on what to do, i just want to ride her:( -Wes

Sounds like you are not decompressing the valve. Look at the manual and check the assembly is exactly like the picture. The lever just sits on top of the cup. Did you try to move the lever on the motor with your hand, not from the handle bar. It may be the cable is out of adjustment and not pushing it down far enough also.

the lever and everything is working fine but i noticed in the manual that there is an oil seal-


it look realy big in the picture and looks like it goes on the outside of the case and i look on my bike and all i can see is the spring and the lever, no seal. can someone take a picture of there decompression valve lever and spring thats on there motor so i have something to compare it to:) also i after searching for a few haours on the forum i found this post-

The occasional failure to decompress properly is generally associated with a stall condition. If the engine stalls against compression, which it's actually pretty likely to do at low rpm under a load, it may come to a stop so abruptly that the decompression mechanism doesn't have a chance to reset itself before the engine stops. This will trap the decomp pin in the retracted position, and the flyweight return spring simply isn't strong enough to force the exhaust valve off its seat. The cure is either to slowly push it through compression, or to put it in gear and rock the bike backward away from the compression stroke, allowing the auto decompressor to fall back to its starting mode.

If, OTOH, the bike is now consistently very hard to turn over, and it's just since the work was done, there may be a problem with the auto decompression unit, or the timing of the exhaust cam. If that's the case, you should talk to the service manager.

it describes my whole problem and i tried rolling the bike backward and it works, i can start moving the kickstart again but the decompression lever still isnt letting me decompress it to kick it:( -Wes

Not sure then, I just had my 426 apart to rebuild. There is not a whole lot going on in there, the lever just pushes the valve bucket(cap) down to release the pressure in the cylinder. The quote seems like it is for an auto decompresssion cam. Did you remove the cams and chain? Did you get everything aligned according to the manual? Just sounds like something is out of adjustment.

well i got it figured out. i put the bike back together and put her in second and held the decomp lever and just rolled her back a few feet. then the decomp lever started doing its job again and kick her over a good 26 times before she finally started up. thanks a bunch for the help s2P:) -Wes

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