yzf400 motor help i need it bad!

[woodsracer144]

ok so as some of you know now i have a 400ex with a yz400 motor in it.. i think its the wr though...(guy said it is a yz but i can get it to max out..) anyway the two black things on the head where teh cams sit i think its part of the gasket but tehy always pop out... mostly the front one... i dont know what the deal is... it sounded like i was loosing compression the one day when i kicked it cause i could hare air commings out but it wasnt... i dont know what the deal is... the over flow lines ans the breather line at the top arnt pluged or anything like that... there was some like high temp silicon stuff that i saw on there...


anybody have any ideas?

also what are the two spicgots that i will be posting pics of? ones on the intake side by the carb boot the other is on teh carb....

thanks !

[woodsracer144]

http://i374.photobucket.com/albums/oo185/mornin151/102_1713.jpg

http://i374.photobucket.com/albums/oo185/mornin151/102_1714.jpg

http://i374.photobucket.com/albums/oo185/mornin151/102_1718.jpg
http://i374.photobucket.com/albums/oo185/mornin151/102_1722.jpg
http://i374.photobucket.com/albums/oo185/mornin151/102_1707.jpg

thanks for any one who can help me out..

[ss440ex]

Not sure if I`am under standing all of your questions....
The two black 1/2 moons are gaskets, if they are blowing out, ck for the two vents on top of the engine.
The rocker box cover has two vents...do not cap them off!
They must breath.

Not sure on the carb fitting...sorry.

Good luck.

[jrspawn]

Im guessing your problem is the valve cover gasket? Your having the half moon sections blowing out? First thing you want to do is replace the valve cover gasket! Once these thing get out of shape, pulled on and off too many times, or get a bunch of silicone gooped up on them your gonna have some problems. Replace the gasket and i think youll find that it was the problem. And when you put the New one on, dont use any silicone if you can. Ive seen too many times people thinking silicone will seal it up and they put too much on and end up pushing the gasket out of its groove and either cutting or pinching it.

Thank you
Justin

[hontrx265r]

your pics are too blurry but the one in front of the carb on the head is a port for the hot start. 400 heads have it on the head 426 they put the hot start on the carb. ( if it doesn't have a hot start on it now, plug it!)

[ss440ex]

It sounds like jrspawn summed it up..
I mis read the part about the silicone.
R&R the gasket for a start.

[woodsracer144]

ok the spickgot is pluged now but theres another one on the carb pluged and theres a jet in it its a 90... whats that for? how much are the gaskets? thanks and the breather tubes are open.. one goes to the oil tank and the others a breather...
there was silicon on it and then it poped out when i was riddin hard on it one day and now if i pop it back in it pops out again... and its only the one closer to the exhaust the intake one is fine... i dont know what the heck is up with it... my cam i can find the auto focus on it... i'll try some better ones soon... thanks