Honda ATV Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter · #1 ·
i have an 04 400ex and was told when i bought it that it has a 440 kit on it but the cylinder says 397cc on the outside. i dont know what to look for on the piston. but i cant measure piston- to- bore i dont have the tool.
 

·
Registered
Joined
·
1,419 Posts

·
Premium Member
Joined
·
4,389 Posts
Well if you have the head off and can see the piston is it a flat top? If it is its almost certainly a stock piston. Stock bore is 85mm and a 440 kit is 89mm that much difference could be measured with a tape measure straight across the bore. The proper way is to use dial calipers but if it is a 440 it will be pretty obveous. Alot of time people claim big bore kits but there isnt anything done to it at all. Which i dont undrstand because if someone says it has a 440 kit i turn and sprint in the other direction. I am yet to see even one person do one right and you will be changing headgaskets weekly. My .02
 

·
Premium Member
Joined
·
1,151 Posts
Harbor freight has cheap calipers for a couple bucks. I wouldn't recommend them for machine work but would certainly measure your piston.
 
1 - 4 of 4 Posts
Top