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deis
02-12-2006, 09:05 AM
i recently installed a 440ex big bore kit and it was jetted to 175 main and 42 pilot and it over heated 20 min into the first ride. what can i do to prevent overheating? i have an overside oil tank and air scoops, yoshimira pipe and k&n intake, the head is ported and polished. 12.5:1 compression. I live in utah at about 4500 ft and the average temp is 30 - 45 degress. I'm starting to think it's not the jetting and could be something else. any suggestions.
LightningEX
02-12-2006, 09:21 AM
I have a couple ideas Ill throw out for you.Get a extra capacity oil tank,try that oil cool stuff.(Dennis Kirk has it)Get air scoops that are designed for getting wind in not looks.I guess you could check your plug gap,oil viscosity etc.I know this cant be much help really but I tryed.Good luck.
humblesquirel21
02-12-2006, 11:54 AM
try another rejet my 300 would overheat alot when i didnt have my jeting right i know u siad u had diferent jets but it sounds to me like ur lean also what fuel are u runing the higher the octane the cooler the engine will stay
nat78
02-12-2006, 03:43 PM
what compression 440 do you have?
balls2da-wall
02-12-2006, 05:05 PM
I ran exactly what you have and ran 2 years worth of XC races on it and never had it over heat. Must be jetting...running lean
2004exrider
02-12-2006, 07:08 PM
Man, you guys need to read everything not just parts. He said its got 12.5:1 comp and he has air scoops and bigger oil tank:p . Yeah deffinitely check the plug to see how its running. What octane are you running in it, also did you advance the timing on it any?

Jimmy
nat78
02-12-2006, 07:22 PM
:tired:
jordan_m6
02-12-2006, 07:30 PM
where do you live. cause i am running a 175 jet on 112 octane and i have a stock oil tank. with a 11:1 stock bore and a cam
400ex7
02-17-2006, 06:54 AM
Anytime you increase the compression you increase the amount of heat the engine builds. Try the oill cooler from Mickey Dunlaps four stroke tech.
mikeysnide
02-17-2006, 08:37 AM
i have the 175 main stage two hot cam and the wiseco 440 bigbore kit and yoshi pipe with a k&n and outwears and i have no prob with mine over heating im gettin ready to go bigger on the jet and remove the airbox lid...and i also have the stock oil tank.

no problem out of mine i love it, its a bad beast