'86 YFM225S Cam Timing Question
#1
'86 YFM225S Cam Timing Question
Finally got the rings in the mail and installed, ready to get this old quad running again. Problem is, I haven't worked on it for nearly a month now and forgot how the cam timing is set.
- What is the mark on the cam to be pointed at..."F" or "T" (with piston at TDC of course)
- Also, how are the valves to be positioned? Both closed, Overlapped with intake or exhaust open? I'm having quite a brain fart right now.
Can someone give me a quick walkthrough on how to properly do this, this is the first small engine I've worked on. I mainly have rebuilt diesel enines and haven't done much with timing..enough to get it instilled into my brain :P
- What is the mark on the cam to be pointed at..."F" or "T" (with piston at TDC of course)
- Also, how are the valves to be positioned? Both closed, Overlapped with intake or exhaust open? I'm having quite a brain fart right now.
Can someone give me a quick walkthrough on how to properly do this, this is the first small engine I've worked on. I mainly have rebuilt diesel enines and haven't done much with timing..enough to get it instilled into my brain :P
#2
Set the crank with the piston at TDC, make sure the piston is at the top. I'm not familiar with your quad but most have a "T" and a "F" stamped into the magneto. The T is "top" and the F is "fire". Line it up with the "T". The valves should all be closed, and line up your cam gear marks, then you should be all set.
You don't want your valves open when the piston is at the top, this could cause the piston to give the valves a hi-five = catistrophic failure!!!! It's good to turn the engine over with a wrench a few times to make sure nothing binds up before you try to crank it with the starter.
You don't want your valves open when the piston is at the top, this could cause the piston to give the valves a hi-five = catistrophic failure!!!! It's good to turn the engine over with a wrench a few times to make sure nothing binds up before you try to crank it with the starter.
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