11:1 426?

[YFZ-FoFiddy-TC]

I know very little about 400's so someone help me out please. My dad wants an 11:1 426 piston for his bike and I need to know if it's an 88mm. Also want to know if he can run pump gas at 4500ft in Utah. He has the jug already but it's stock crank and every 88mm piston I find says stroker?

Thanks,
Anthony

[CJM]

.120 over, 88mm piston is 426. Not sure what your finding. Should be fine to run pump gas. Id do a 416, 426 is not a huge increase in power over 416 and then you can at least bore it one more time to 426. Anything over 426 is either a new sleeve bqack to stock or a 440 kit.

[YFZ-FoFiddy-TC]

He wants a 426 so that's what he gets. He already has a 426 jug.

[mineralgrey01gt]

id love to know where your getting it needs a stroker crank? I never heard that one before

[01boneless]

make sure to tell your dad to get HD studs or he will blow headgaskets left and right. also since they get hoter get a oversize tank and fan on the oil cooler or it will over heat good luck!! :cool:

[YFZ-FoFiddy-TC]

Doesn't say it needs a stroker crank it just says 88mm stroker? I'll keep looking around. I'll call up KB Monday.

[ish416]

Here is what you will need.

Head studs
http://www.gtthunder.com/TRX400EX.htm

Scroll down and you will see head studs. They are $59.95 plus installation if you cannot install them yourself.

Piston
http://www.kbmotorsportsonline.com/engine/pistons/je-pistons.html

It will be the 6th one under Honda. $131

Gaskets
http://www.kbmotorsportsonline.com/engine/gaskets/cometic-top-end-gaskets.html

Select the 2nd 400EX gasket. Do not select the 89mm. That is for a 440. $30.84

Total = $221.79

Also, if your dad already has an 88mm jug then I would hone the cylinder unless that has already been done recently.

As far as 11:1 compression, I can't be of much help as all I can tell you is that 11:1 on 93 is perfectly fine at my altitude (1100 ft). A larger oil cooler and SPAL fan are both highly recommended.

[YFZ-FoFiddy-TC]

Thanks for the help. Don't need a gasket kit or head studs as he already has them.