Blown 331
05-28-2005, 01:04 PM
My cousin bought a 1999 440EX and the owner said it was fine on 93 octane. My cousin put 93 in it and is spark knocked so he started running 110 but it was too late and blew the head gasket and cracked the piston (JE). .
He got it back together with a 11.2 to 1 Powroll kit. At this time he ported the head him self and put on a flat slide carb from a CRF450. It didn't run like it should, he tried swapping carbs back and that didn't really help. He was running 110 in that but put 93 in it when he ran out of gas and blew that head gasket too! He put a stock head on it thinking his port job messed it up but that didn't help and he blew another gasket. Well the bike is sitting apart and we're not sure what to do with it. He wants to run pump gas but it has the worst spark I've ever heard. I'm talking in first gear you give it half throttle and all you hear is spark knock, it's crazy!
He bought another 440 cylinder off ebay for next time around. He also has the biggest cam web cam makes and his valves have been making slight contact with the pistons, both set ups. He thinks that cam is preventing it from making power like it should, too big. But that cam is still no where near the size of the HRC cam in my 450R, so I'm not so sure that's it.
I think it should run on 93 octane with 11.2 to 1 compression. He has tried 2 heads to I don't think he has a milled one. We also check to see if it had an advanced flywheel key, nope. Any ideas why this thing spark knocks so bad? He is thinking about running 2 head gaskets and like 6 base gaskets. lol. Looking for some imput here.
He got it back together with a 11.2 to 1 Powroll kit. At this time he ported the head him self and put on a flat slide carb from a CRF450. It didn't run like it should, he tried swapping carbs back and that didn't really help. He was running 110 in that but put 93 in it when he ran out of gas and blew that head gasket too! He put a stock head on it thinking his port job messed it up but that didn't help and he blew another gasket. Well the bike is sitting apart and we're not sure what to do with it. He wants to run pump gas but it has the worst spark I've ever heard. I'm talking in first gear you give it half throttle and all you hear is spark knock, it's crazy!
He bought another 440 cylinder off ebay for next time around. He also has the biggest cam web cam makes and his valves have been making slight contact with the pistons, both set ups. He thinks that cam is preventing it from making power like it should, too big. But that cam is still no where near the size of the HRC cam in my 450R, so I'm not so sure that's it.
I think it should run on 93 octane with 11.2 to 1 compression. He has tried 2 heads to I don't think he has a milled one. We also check to see if it had an advanced flywheel key, nope. Any ideas why this thing spark knocks so bad? He is thinking about running 2 head gaskets and like 6 base gaskets. lol. Looking for some imput here.