sheerider1026 Posted March 15, 2009 Report Share Posted March 15, 2009 you need to check squish.. since the problem starte after you installed the head, sounds like squish is off, or compression is too high.. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted March 15, 2009 Report Share Posted March 15, 2009 (edited) detonation can be cuased by ; not enough gas not good enough gas (octane) too much compression too much timing over heating hot spots in combustion area load Edited March 15, 2009 by dirtydownunder Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted March 15, 2009 Report Share Posted March 15, 2009 yep.. if i leaned my bike down.. i am willing to bet i would get some detonation.. tuning can be tricky, but rewarding when you get it right.. check your squish.. throw more fuel at it.. maybe throw a 340 jet in it, even if its rich, you can work your way down .. +4 timing sounds acceptible for this bike. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted March 15, 2009 Report Share Posted March 15, 2009 if they started backing out after you switched from a stock head to a cool head, its detonating. try some race gas and see. then once you know thats the problem, go to a 21cc dome. no need to go all the way up to a 22cc. Quote Link to comment Share on other sites More sharing options...
captainhowdie Posted March 15, 2009 Report Share Posted March 15, 2009 if they started backing out after you switched from a stock head to a cool head, its detonating. try some race gas and see. then once you know thats the problem, go to a 21cc dome. no need to go all the way up to a 22cc. I have some 22cc domes if you are interested. Ill sell em $25 shipped. There like new, noss/prodesign PM me if interested Quote Link to comment Share on other sites More sharing options...
sheefreak Posted March 15, 2009 Report Share Posted March 15, 2009 Need to check squish. What size base gasket did you use? You should be able to run that setup on premium fuel. A leaky o-ring will also cause deto and plugs to back out... Quote Link to comment Share on other sites More sharing options...
twizted269 Posted March 16, 2009 Author Report Share Posted March 16, 2009 Need to check squish. What size base gasket did you use? You should be able to run that setup on premium fuel. A leaky o-ring will also cause deto and plugs to back out... to be honest i have no idea how to check the squish so i will have to look into that. base gasket is just a standard gasket made by cometic. orings seem to be fine. made sure everything was set very carefully before torqued down. im thinking compression. Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted March 16, 2009 Report Share Posted March 16, 2009 squish is the measurement between the piston and some at TDC.. you want to measure the squish on the outer edge of the piston.. you can use a piece of solder, fish it down through the sparkd plug hole, making it bend over to the edge of the cylinder, get someone to turn the motor over by hand, the piston will flatten the solder out, then measure the thickness of the solder, this measurement will be your squish.. hope that helps. Quote Link to comment Share on other sites More sharing options...
'04limited Posted March 16, 2009 Report Share Posted March 16, 2009 squish is the measurement between the piston and some at TDC.. you want to measure the squish on the outer edge of the piston.. you can use a piece of solder, fish it down through the sparkd plug hole, making it bend over to the edge of the cylinder, get someone to turn the motor over by hand, the piston will flatten the solder out, then measure the thickness of the solder, this measurement will be your squish.. hope that helps. also your gonna want to make sure that the solder is parallel with the wrist pin when you do this. Quote Link to comment Share on other sites More sharing options...
docjcwatson Posted March 16, 2009 Report Share Posted March 16, 2009 i use a wrench for the plugs. i changed them out on the trail today and they look golden brown. I tried using an adjustable wrench on my plugs and they kept backing out. I thought they were tight enough. Eventually I broke down and bought a socket. No more problems. Quote Link to comment Share on other sites More sharing options...
twizted269 Posted March 16, 2009 Author Report Share Posted March 16, 2009 also your gonna want to make sure that the solder is parallel with the wrist pin when you do this. ill check it as soon as i get back into town. what should it be at normally? or range? Quote Link to comment Share on other sites More sharing options...
Building my First Posted March 17, 2009 Report Share Posted March 17, 2009 If every thing else is right. How many times have you had those plugs out? I had the same problem last year with my first build, everything was stock. I had the plugs out lots of times just nervous and makeing sure jetting was right. It was my first build and I did everything myself. Anyways the plugs kept getting loose after it was broke in, I guess the crush ring wasn't locking any more. I put new plugs in and never had the problem again, I guess you can only torque them down so many times. Quote Link to comment Share on other sites More sharing options...
jjn56 Posted March 18, 2009 Report Share Posted March 18, 2009 im just running the standard br8es plug. what are the main causes for detonation? the only thing ive changed for this problem is the cool head. jetting was always pretty rich with the stock head. im pretty set on going to 22 cc domes and get it closer to stock compression. fly wheel key is also fine. checked that for another problem i had. How could you know you are running rich if you have never done a plug chop? I think you need a to try larger jet I'm running a 300 at 1000 feet and don't have nearly as many mods as you. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 18, 2009 Report Share Posted March 18, 2009 No one has mentioned an air leak.... Quote Link to comment Share on other sites More sharing options...
Ineedmoney Posted March 18, 2009 Report Share Posted March 18, 2009 Ok i dont know if this is what he is tlaking about. But every once in a while i will pull my spark plug cable off of my spark plug. The little twist thing at the top of the plug will come unscrewed a little. Is that the same thing he is tlaking about. Quote Link to comment Share on other sites More sharing options...
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