engine trouble

[honda250xrider]

hey guys i was wondering if you could help me on a few things, alright i can turn the motor over and it will start to suck in... then when the intake vavles should close they just let the air back out the intake.... now could you tell me why it does this.... also the timing is correct... does this mean i need new seals or what? thanks alot

[josh]

that's a strange diagnosis, could u give a lil more detail, what about ur spark plug, check that for fitting, i've never heard of air pushing back out the intake, if that's what ur saying, if that's it i would check the rockers, did u put em in or make sure they are in right, and what about the decompression tube for starting, without more information i can't give any more opinions, but run a good check of everything, did u just rebuild the motor and ur having problems, or did it just start throwin a fit on ya, w/e it is i've never heard of that though, also check the cam and how it lines up with the rockers and valves, maybe somethings loose and the valves are just kinda floppin at one point, that's my best guess with the information stated

[ghak99]

More info would help. From what you just said I would say you need to check the valve lash, If it is too close it can keep the valves open too long. Hope this helps!

[honda250xrider]

i have taken the decompression cable off.... always have started right up without it.. i had just got it back from the mechanics.... yes the rockers were put in right... i had the mechanic double check with that cam lines up with the rockers and everything... i had taken it back to the mechanic twice because of this im still puzzled as to why it does this

[ghak99]

I am goin out on a limb here.......If this motor was just put together then who ever did it might have put the valves in wrong. If the exhaust and intake valves are switched they would not seal right. Here is something simple you can do to help figure out the problem. Use a rubber tipped air nozzle and put this in the spark plug hole and pressurize the cylinder. listen for the leaking air and where it is coming from. The motor has to be at tdc for this to work. Hope this helps

[ghak99]

What is the valve lash set at for the intake and exhaust?
And was it done while at top dead center?