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440 for stock 400ex plus cash
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Posted by: TheBlasterMan

I am getting a 400ex but it has a 440 kit on it. It has stage 3 cam, heavy duty studs, new clutch, bottem end just rebuilt, high compression piston 12.5:1 and some other things that i cant remember. I am looking to trade for a 400ex motor that is stock plus some cash. This motor is off a 1999 ex

Posted by: Chino886

quote:
Originally posted by TheBlasterMan
I am getting a 400ex but it has a 440 kit on it. It has stage 3 cam, heavy duty studs, new clutch, bottem end just rebuilt, high compression piston 12.5:1 and some other things that i cant remember. I am looking to trade for a 400ex motor that is stock plus some cash. This motor is off a 1999 ex

How much cash, see my sig, it is stock bore.

Posted by: TheBlasterMan

Im not sure how much should i ask for?

Posted by: Chino886

I don't know, bigger=unreliable, smaller=less power! Big toss up!

Posted by: murrays400ex

just for ur info 12.5 to 1 is not high compresion like 13or 13.5 and uop is race gas and u have 2 run race gas

Posted by: TheBlasterMan

with 12.5 what do i have to run? Octain?

Posted by: Derag2

91 minumum, 93 would be better but not all places sell 93.....

Posted by: TheBlasterMan

so im not going to screw up the moto if i run 93?

Posted by: khen

At 12.5:1 on the 400EX you are going to need to run at least a 50/50 race gas and premium mix. With my 11:1 I have to run 50/50 or it pings like mad.

Posted by: 400exrider707

Yeah 12.5:1 is race gas territory. Im not a big fan of mixing gas

Also I wouldn't even bother with that thing unless it has a heavy duty rod running the 12.5:1 piston. What other motor work exactly does it have???

Posted by: TheBlasterMan

it has a heaavy duty rod
engine was made to race, only raced gncc once, it was just rebuilt.

Posted by: Chino886

quote:
Originally posted by TheBlasterMan
so im not going to screw up the moto if i run 93?

If it were my motor, I would only run race gas in it, being that a 400 is air cooled, you don't want to risk detonation. I have read that anything over 11:1, you should run race gas.

Posted by: 99_300ex

ya i heard the same as chino.

Posted by: TCracin440ex

quote:
Originally posted by murrays400ex
just for ur info 12.5 to 1 is not high compresion like 13or 13.5 and uop is race gas and u have 2 run race gas

bull chit....with a 12.5:1 you have to run race gas...its considered high compression....with a 11:1 ratio you wont have to run race gas...