milled head

[slow416ex]

has any body milled their head or jug to bring compression back up i have the je 10.8:1 piston and slowed way down till i milled it down then it really picked also have 479 web cam with muzzy pipe with 180 jet

[Chanman420q]

i think you can only do that to a 2-stroke, or maybe im just thinking of shaving the head?:huh but im pretty sure thats a 2 stroke thing

[PHIL_B54]

http://www.exriders.com/vbb/showthread.php?s=&threadid=48435

i dont know much, but that thread might help

[chad502ex]

Originally posted by slow416ex
has any body milled their head or jug to bring compression back up i have the je 10.8:1 piston and slowed way down till i milled it down then it really picked also have 479 web cam with muzzy pipe with 180 jet

yes, milling the head 0.020" can bump compression as much as 1:1 (or from 11:1 to 12:1). The bottom of the stock head has a volume of 48cc, so milling the head 0.020" will reduce the heads chamber volume to about 46cc. Don't sound like much, but it is!!Combine this volume with the cylinder volume and consider the dish or dome volume in your piston and you'll obtain the compression ration. It's a little more than this, but I'm just summarizing for ya. Another trick, is to get a thinner head gasket to pull the head closer, or remove the base gasket completely. Removing the base pulls the whole top end down.

Caution: If you remove the base, install thinner head gasket and shave the head, your cam chain slack could be too much. Also, the valves could slap the top of the piston if your not careful.

Hope this helps. :)

Chad502EX.com

[hawiianpwr]

Hey slow416ex how do you like your muzzy pipe? Does it sound good? Its looks like a sweet pipe.