YT175 head

[RubberSalt]

I was woundering how much I can get milled off my head. If I've gotten no answer by Friday, I'm going to get 20thousandths off.

[RubberSalt]

No one knows how much to mill off the head.. Dang:\

Guess I'll have to start doing that math again.

[Vealmonkey]

This is one of those kinds of questions no one likes to answer. You can be opening up a whole can of worms here. If you really aren't running the trike for competition, I would say for your wallets sake and your engines sake, to not really do this. It's definitely not something you would do to an engine that does not have a fresh lower end. Increaded compression can put alot of strain on old tired parts, meaning engine failure. You have to figure your engine is over 20 years old and has probably never had the bottom end apart. A recipe for disaster. You can accomplish quite alot by freshinging your hole engine up top to bottom and porting and polishing your stock piston and cylinder or going to a different piston and cylinder from another yamaha that will bolt on to your trike that gives you better porting and port timing stock. So please think twice about milling your head.