Hello,
I have a -06 KX250 with about 25-30 hours on it. I'm approaching the first top-end change and was thinking about having the head machined for a bit more compression because I would like more grunt. I hear the stock heads have pretty low compression to take into account the crap fuel people put in the bikes.
I intend to use Shell V-power 99 octane ( http://www.shell.com/static/fi-fi/downloads/tt/v_power.pdf , the PDF includes the information in English as well as in Finnish and Swedish) fuel mixed with 2% Motorex Cross Power 2T ( http://www.motorex.com/index.cfm/fuseaction/show/path/1-418-443-772-785-799 ).
The real question is, how much to shave off the head? A riding buddy had 2mm taken off his -05 YZ250 and that bike is running great. Obviously I would rather not take too much and have the bike ping itself to death.
How about advancing the ignition? Any experiences with the KX? How do you generally do this? Twist it a tiny amount, fire the bike up and check for detonation and repeat?
I have a -06 KX250 with about 25-30 hours on it. I'm approaching the first top-end change and was thinking about having the head machined for a bit more compression because I would like more grunt. I hear the stock heads have pretty low compression to take into account the crap fuel people put in the bikes.
I intend to use Shell V-power 99 octane ( http://www.shell.com/static/fi-fi/downloads/tt/v_power.pdf , the PDF includes the information in English as well as in Finnish and Swedish) fuel mixed with 2% Motorex Cross Power 2T ( http://www.motorex.com/index.cfm/fuseaction/show/path/1-418-443-772-785-799 ).
The real question is, how much to shave off the head? A riding buddy had 2mm taken off his -05 YZ250 and that bike is running great. Obviously I would rather not take too much and have the bike ping itself to death.
How about advancing the ignition? Any experiences with the KX? How do you generally do this? Twist it a tiny amount, fire the bike up and check for detonation and repeat?