I stuck a screwdriver in spark plug hole to find tdc as my timing marks didn't seem right to me at all. With verification of tdc from the piston movement all the way to the top, i have this in the picture. I linned up the valve gear with the flywheel as best i could, it wasn't lined up perfectly. Do i have a fly wheel key offset about to break? As you can see in the picture the timing mark is far left of line up marking. Im rather confused because the 4 wheeler was running before i had crank case pressure issues.....

 

You would have to be very accurate with your TDC measurement by piston to get it closer than that. The piston hardly moves at all +/- 5 degrees of TDC. Try again, turning the piston in the other direction and see if you get the same reading on the flywheel.

 

I have tried about 100 times now lol. I have been in industrial maintenance for 12 years, and i was a helicopter mechanic for 7 years before that. The flywheel is definitely off from tdc. Any ideas why?

 

Got to be the key on the flywheel, unless the makers are a bit lax with their markings. Only one way to find out and that is to remove the flywheel and look. Because the electric start tries to turn the flywheel, there is a fair bit of torque put on that taper. If it isn't tight enough, this is transferred to the key. I have known them to be 180 degrees out when the key shears. If they have given trouble, I lap the tapers together with valve grinding paste. Always torque them up on assembly as, too slack and they will slip, too tight and they are almost impossible to remove.

 

If the key is offset as much as the picture above shows, would the atv still run you think? Second question: say the key is fine, what would my next step be? For example lets say the flywheel had no timing marks at all, how would i go about finding the proper timing for the magnts on the flywheel?

 

If the key is OK the mark must be out (or your readings, I couldn't say to 5 degrees, if the piston is at TDC without a dial test indicator). The pip for ignition timing could be out, or it may be correct, if the bike ran OK before the "crankcase pressure issues" ignition timing must be pretty close. As for valve timing, set it to your judgement of TDC if you want to, but it won't be more than 1 tooth out, if set to the TDC mark.