I plan on getting a 440 kit w/11:1 JE piston and was wondering if I can run my stock exuast with it for a while until I have enough money for an aftermarket pipe. This is when i do the least of my riding and want to have my bike back together when the weather gets better around here.

Steven
99 400EX, Works triples, power kit, renthal bars, etc.

 

As far as I know, it will work. You just won't have the power of a pipe along with it. Let us know if it works. I want to get the 440 kit but I don't want the noise of an aftermarket pipe.

 

Did you do the kit yet? Waiting impatiently in DSM.

 

Don't have the kit yet, because I was supposed to sell my 300EX this week and the guy didn't buy it. When I do get the kit, I 'll write a report about it on here.

Steven
99 400EX works triples, power kit, renthal bars, studded XCT's, etc.

 

Your stock pipe will work well with the 440 kit. We're pretty much stuck with the stock exhaust on the 400 here in Oregon, because of the tight sound restrictions at the Oregon Dunes.

We've built about six 440 kits utilzing the stock exhaust -- they're not quite as quick on top end, but actually have a little better torque compared to the same kit with an aftermarket exhaust.

 

Pam, are you using high comp. pistons with those? I was just wondering becuase I think I am going to go with 11:1 JE.

Steven
99 400EX works triples, renthals, power kit, XCT's studded for winter, etc

 

People say that the JE is way better than the Wiseco for durability. At 11 to 1, don't you pretty much have to run 50/50 race gas? I had a 10.25 to 1 piston in my Warrior and I used 91 octane. I didn't want to use race gas so I went with lower compression.

 

Steven,
Yup, that's running with the 12:1 compression pistons.

 

The 400EX seems to be able to handle 11:1 on premium pump fuel. Because of the great RFVC head design, it keeps everything a little cooler.

I have seen cases of detonation on a 400EX with 11:1 pistons if someone gets crummy fuel, so if it were my quad, I'd probably run 1/2 & 1/2.

The Warrior really has problems with high compression -- so you're right, anything over about 10.5:1 needed a little more octane than you could get from even the best pump fuel.