Daredevil1
02-23-2004, 09:41 AM
Hi,
I just bought my 400ex at the beginning of last season on the assumption that it had a CT440 High output kit in it (the good one). I rode it this season, and being new to four strokes I didnt really know what the power was supposed to feel like. Well anyways I took it apart for the winter rebuild to check clearances and there wasnt anything in there except a 440 cc bore and a JE 89mm 12.5:1 piston. Stock everything else! I was shocked and pissed at the same time. No cam, no porting, no hardened rockers, no CT valves, stock springs, stock clutch (oh yeah it was supposed to have hinson with a barnett pack), no nothing.
So from here I want to do some porting and other head work. I was looking at having Curtis Sparks do his 440 national porting (because I already have the JE 12.5:1 piston he uses in his kits) along with hardened rockers, his national cam, and a heavy duty timing chain, and obviously clutch work.
The question I have is that Sparks said that it is necessary to have a heavy duty connecting rod put in, but how necessary is it? Can I go without and still be ok? The other question is...Does anybody know what piston-cylinder clearances I should have between the JE piston and the 440 bore? Thanks for your help
Adam
I just bought my 400ex at the beginning of last season on the assumption that it had a CT440 High output kit in it (the good one). I rode it this season, and being new to four strokes I didnt really know what the power was supposed to feel like. Well anyways I took it apart for the winter rebuild to check clearances and there wasnt anything in there except a 440 cc bore and a JE 89mm 12.5:1 piston. Stock everything else! I was shocked and pissed at the same time. No cam, no porting, no hardened rockers, no CT valves, stock springs, stock clutch (oh yeah it was supposed to have hinson with a barnett pack), no nothing.
So from here I want to do some porting and other head work. I was looking at having Curtis Sparks do his 440 national porting (because I already have the JE 12.5:1 piston he uses in his kits) along with hardened rockers, his national cam, and a heavy duty timing chain, and obviously clutch work.
The question I have is that Sparks said that it is necessary to have a heavy duty connecting rod put in, but how necessary is it? Can I go without and still be ok? The other question is...Does anybody know what piston-cylinder clearances I should have between the JE piston and the 440 bore? Thanks for your help
Adam