robert0762 Posted April 14, 2009 Report Share Posted April 14, 2009 How much comp. can I run on pump gas with +4 timing? Quote Link to comment Share on other sites More sharing options...
TwistedSheeRida Posted April 14, 2009 Report Share Posted April 14, 2009 wouldnt go over 165 if you advanced the timing i would run race gas anyways or at least mix it half and half Quote Link to comment Share on other sites More sharing options...
twizted269 Posted April 15, 2009 Report Share Posted April 15, 2009 it really depends on how everything is set up and the mods. do some research and youll learn enough to feel safe. Quote Link to comment Share on other sites More sharing options...
87sheerips Posted April 15, 2009 Report Share Posted April 15, 2009 wouldnt go over 165 if you advanced the timing i would run race gas anyways or at least mix it half and half I agree with this. I ran my trail bike at 165psi, +4 timing for years without issues. Hell my buddy was running his bike at 175psi on pump gas. I wouldn't do it, but he as well had zero issues with detonation or anything related to low octane. Quote Link to comment Share on other sites More sharing options...
maxtrax Posted April 15, 2009 Report Share Posted April 15, 2009 (edited) I know someone that is running over 165+ with +4 timing on 93 octane. I don't think I would but he's done it for years. If I went anything over 160-165 I think I would at least mix with race gas to be safe. On my current bike I have about 140psi with +4 and I am using 93 without any trouble. Edited April 15, 2009 by maxtrax Quote Link to comment Share on other sites More sharing options...
johnny boy Posted April 15, 2009 Report Share Posted April 15, 2009 (edited) it really depends on how everything is set up and the mods. do some research and youll learn enough to feel safe. that is the truth there..i have a aggressive dune port from her jugs,20 domes,150 psi,+4 timing..and i have to run 70/30 mix(110 race fuel and 91 octane)..learned the hard way ...all depends on the mods Edited April 15, 2009 by johnny boy Quote Link to comment Share on other sites More sharing options...
robert0762 Posted April 15, 2009 Author Report Share Posted April 15, 2009 (edited) I'm planning on getting a cool head soon and want to know ahead of time what size domes to get. I'm on stock port 80 over . got some pro circuits on the way and have a k+n with the lid off. Next winter I'm gonna go with a 4 mill and a mx port on a fresh set of juggs but till then I want a lil more go then what she has now. Edited April 15, 2009 by robert0762 Quote Link to comment Share on other sites More sharing options...
robert0762 Posted April 15, 2009 Author Report Share Posted April 15, 2009 Does advanced timing cause you to deto earlier or vice versa??? Quote Link to comment Share on other sites More sharing options...
maxtrax Posted April 17, 2009 Report Share Posted April 17, 2009 Does advanced timing cause you to deto earlier or vice versa??? The timing advance causes the gas fuel/air mixture to ignite earlier. There is a difference between ignition and detonation. Detonation is caused when the compression is too high for the octane rating and it spontaneously combusts. Ignition is caused by the spark plug. A higher octane fuel will take slightly longer to burn and give you a more consistent power and more even heat distribution throughout the engine. If you run too low of an octane in an engine with timing advance, the fuel will give too much power before the piston reaches the top and cause excessive strain and heat. Hope that helps you some Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.