Time to freshen up....

[sly400ex]

Time for more power! I have a 2001 400 that can use a little new life.

Last year I let this girl ride my quad and she made it scream in pain by riding it in 1st gear wide open for a good amout of time. Now it burns about a 1/2 quart every few hours.

So my question/s is.

What is the absolute highest compressioon piston I can run on 92 octane?

What else should I need besides a piston, cam, gasket kit.

Will I need rockers/valves/seals?

I want to go with a hot cams stage II. I still want my bottom end with more top.

A 416 piston kit, Ross most likely.

cometic gasket kit, but should I get it for a 400EX or XR400...I heard the XR400 is a little thinner yielding higher compression. I figure my motor has a ballpark or 1500 hours on it, just fyi. Thanks!

[hondarider2006]

sounds like the set-up you are building...is something similar to the 416 I built. As far as the compression goes....I wouldn't go the HIGHEST possible....because of head stud problems, and blowing head gaskets. I ran a 10:8.1 and currently running a 11:1 and they both had awsome low end. I also run the Hot cam stg. II and it worked awsome with the piston kit. You might want to replace valve seals, and while your getting your cylinder bored, you mise as well have a valve job done just to clean things up. Port and pollish is also somthing to think about...if you have the skill, do it yourself...if not you can fork out some $ and have it done;)

[stc416rider]

i have 4 carbs from a 1979 honda bike

how do u port and polish i can pratice on those

[2004exrider]

porting and polishing is done to the intake and exhaust ports:)

Jimmy

[stc416rider]

oh woops

cant u do something to the carbs to make them better 2

[2004exrider]

no problem buddy, dont quote me but im pretty sure that some places (like edelbrock) can bore a carb over a little bit.

Jimmy

[stc416rider]

y r u the 1 2 always answer my questions

thanks