valve problem on powderlites apex
- Thread starter snojunkey
- Start date
How much boost you running? What is done to the motor?
how much gap do you have? have you checked your shims, looked the valve over to ensure nothing is in the spring and your keepers are seated?
the only way the shims could come out would be if there is too much clearance under the lobe or the valve or spring is binding or the spring is dead.
dont know what you are useing for fuel, how fat you run it or the condition of the engine. My other thought would be that race gas and oil tend to build carbon in the chamber especially if you run it fat, enuff that it can stick rings and hold valves open inlarging your shim spacing then when you wind it up the shims could unseat.
I would say you are lucky nothing has gone really bad since the shim out of place would hold the valve open alot.. julio
the only way the shims could come out would be if there is too much clearance under the lobe or the valve or spring is binding or the spring is dead.
dont know what you are useing for fuel, how fat you run it or the condition of the engine. My other thought would be that race gas and oil tend to build carbon in the chamber especially if you run it fat, enuff that it can stick rings and hold valves open inlarging your shim spacing then when you wind it up the shims could unseat.
I would say you are lucky nothing has gone really bad since the shim out of place would hold the valve open alot.. julio
Sounds to me like it should of gone to someone qualified to put a head shim in and check the valve clearances. You're luck you didnt drop a valve and waste a head and a turbo.... Now that place in oregon isnt qualified......
Then it sounds to me like who ever had the cams out could of lifted a cap or 2 and a few pucks are got cok eyed and then someone put it back together without a full clearance check. there are alot of tricks to this motor game and motor work is only done well by a select few..
?
why are you running race at 12lbs? that is just on the edge of safe with premium( unless you ride at sea level) I bet your sled farts pops and carrys on till you get a climb or two in. at 12 lbs you should be running premium with maybe a splash of race to make you feel better.
is it the same valve that is messing up each time?
Ok wait a minute, are you shure the shims are moving? are YOU taking the sled apart when this happens? If you are taking the sled apart are you checking clearance before removing the cams and caps? ** a shimed motor at 12lbs on race gas = will barely start when cold, will run down the trail at low to mid throttle ok but when you open it up it would fall on its face burping and farting and run like its lost two. It will do that till you get the engine good and hot, three or four pulls up a medium hill trying to get it to run open then repeat if you cruise around for a while.
why are you running race at 12lbs? that is just on the edge of safe with premium( unless you ride at sea level) I bet your sled farts pops and carrys on till you get a climb or two in. at 12 lbs you should be running premium with maybe a splash of race to make you feel better.
is it the same valve that is messing up each time?
Ok wait a minute, are you shure the shims are moving? are YOU taking the sled apart when this happens? If you are taking the sled apart are you checking clearance before removing the cams and caps? ** a shimed motor at 12lbs on race gas = will barely start when cold, will run down the trail at low to mid throttle ok but when you open it up it would fall on its face burping and farting and run like its lost two. It will do that till you get the engine good and hot, three or four pulls up a medium hill trying to get it to run open then repeat if you cruise around for a while.
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yes it dose pop a bit when its cold i run racegas to be on the safe side iam a little skiddesh about melting it down and didnt think it could hurt. and yes the shim is defintley off it trashes the valve shim retainers and guids every time it happens and it happened on different valves both times the first time on an intake and the second time on the exast.
Have you ever had the head off ? Have youever gotten the cam chain on wrong and tryed to start it or turn it over by hand. The reason I'm asking is because I bent a bunch of intakes on my RX1 once when things weren't lined up right. I 'm thinking that you have a bent valve stem and its hangin open long enough to get too much clearance in it. Ken....
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