I just waned to know how much you can have the head milled before the piston will hit the head. Or if anyone can tell me what is the most they have heard of someone taking off the head. thanks. i have to have the top of my jug milled down a little

 

im sure .010-.020 wont hurt anything.

 

well heres the new problem,the machinist milled 20 thousandths off of the top of the jug,and now the piston barely comes out of the cylinder,and bumps the head.i would say now i could mill the head deaper,but the piston rubs the seal a little bit.is there anyway i can use two head gaskets?,or even two base gaskets? or am i screwed

 

It may be better to stack 2 base gaskets to restore the jugs deck height. Though the idea makes me nervous, I have seen it done on my friends TRX250 and it held up fine.

 

does the piston bump the head with the gasket on ? if not put the head on with the gasket and have a pice of soft solder on the piston you can stick it in the plug hole.rotate the moter smash the solder. take it a part and see how thick the solder is. then find out how much clearence you need to have to be safe. that part i dont know. my .02

 

Why did you mill the cylinder instead of the head? Adding base gaskets to fix your deck height will change port timing some. (not a good thing)

as the previous post mentioned, you now need to check your squish clearance (Distance b/w the top of piston, and tapered section of the head) That will probably need to be modified/corrected.

I would strongly recommend seeking assistance from someone who's qualified (done this before) at this point.

 

taking a shot in the dark addict(lol) pryed the jug with screwdriver??? ouchhhhhhhhhhhhhhhh

 

i agree with duneaddict. its time to turn it over to someone with some experiance. your opening up a big can of worms. in tring to fudge this thing together. then the bike will be no fun to enjoy.

 

I actualy contrary to how this sounds, do know what im doing.when i tore it down there were big dents in the cylinder deck.So i had it milled down 20 thousandths(wich is what it took),to re-surface it. Now the piston is coming to close to the head.My only option was to use two base gaskets or two head gaskets. So i asked my friend (who owns and runs a atv/motorcycle repair shop),and he said i would probably be fine,and that he has seen several people use two base gaskets with no problems.I understand what your saying about port timing,but i feel i should at least try it before i go spend 300 bucks on a new cylinder. Would the height diference of just an extra base gasket really make a huge diference?

 

Oh,and it defintely wasnt me who pryed the head off,im not reatarded here just trying not to spend 300 more dollars