I have a 1999 lakota,modded with the following. Suppertrap exhaust,k@n air fiter, dynojet carb kit,cam reworked by web cams,synth. oil,stock tires and gearing,racks removed. I have been looking for a 10 to 1 piston with no sucess. I think i want to have the head milled approx. 20 thousands,and the ports? head cleaned up a little bit.Stock compression is 8.6 to 1. Do you think that it is worth the 150 dollars to have it done?Any thoughts on why it would be a bad idea? I have changed front spockets, did'nt like that,top out way to soon.I have been posting in this forum about a prarrie 400 still plan on getting a new quad for x-mas. Kepping the lakota though.

 

Unless you've calculated the amount of material to be shaved from the head to get to 10.0:1 from 8.6:1, .020 sounds low--oughta take at least .030, I'd think; .020's hardly a clean-up.

I doubt you'd get piston-valve interference; if so, fly-cut the stock piston top to relieve it.

If someone will take down, mill head, clean up ports, provide a new gasket and reassemble for $ 150; jump at it! If they want $ 150 for milliing and port cleaning alone, not quite as good a deal; I'd go with shaving the head only by a competent meachine shop; surfacing the head shouldn't cost much.

Diogenes