Gaskets with the 426 pitson

[powderider87]

Hey guys, well i tore apart my engine and now i am going to buy the piston kit and the gasket kit.. I will be going with the 426 kit. i like this one on ebay

426 ebay kit (http://cgi.ebay.com/ebaymotors/Honda-400EX-426-Wiseco-piston-w-top-end-gasket-kit_W0QQitemZ110207606237QQihZ001QQcategoryZ43977Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem)

But that will take a good week and a half to ge there and im getting anxious. Dennis Kirk is like 2 hours from my house and would like to go thru them but was wondering about that gasket. can i use any 400ex top end gasket kit with the 426 or do i need to have a special one? i was looking at this moose one.

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=&catId=1&productId=p262061&leafCatId=&mmyId=1572


Also what size is the 426 piston? 89mm 86mm 85mm bore

[XXXRACER165]

Idk about the size of the gasket but the piston is 86mm I think. Keep me updated on your re-build, cause when your done I wanna see if we can go riding. I live south west of Dennis Kirk, it be cool if we could share a few riding spots and rip it up at St. croix.

[F-16Guy]

A 426 is an 88mm piston. Why are you going to a 426 right away?? If I were you, I'd go with a 406 (86mm) or 416 (87mm). Preferably the 406 if the bore will clean up with that much taken off. The majority of the extra power will be from the increase in the compression ratio, not the displacement. By going directly to a 426, you're eliminating the possibility of another overbore for a future rebuild. You would then have to re-sleeve and bore, which will cost you much more.
To answer the gasket question, you'd want the Cometic 89mm gasket set for an 88mm or 89mm piston.
My advice would be to buy an 11:1 Wiseco (or JE) 86mm piston, a stock size Cometic top end gasket set for an XR400R, and a HotCams stage 1 or 2 cam. That will give you a huge increase in power.
Don't buy the Moose gasket set. It has a fiber head gasket that most people agree is not as good as the 3 piece steel version. Either buy an OEM Honda gasket set, or get the Cometic set with the MLS (multi-layer-steel) head gasket, which is basically the same as OEM.

[fastredrider44]

I have a cometic MLS gasket kit in my 426. The gasket set said 89mm, so it was for a 440, but works fine in mine.

[powderider87]

Hey guys, well i put off the rebuild for a while now but im ready to do it... i just dont want to order the wrong stuff. Can someone give me some links to either a whole top end rebuild kit for a 426. or maybe the piston kit and a gasket kit. i just want to get the right size gasket and piston for this thing without screwing something up. Thanks a lot for helping out.

[Honda#4]

I agree with F-16guy. In the long run it will be cheaper if you go with a 406 or a 416 first.

[powderider87]

ok the 406 or 416 sounds good i just want a high comp piston and all the right gaskets and what not and get it done soon. let me know what to get for the 416 kit, like what size gaskets.

[Honda#4]

Well Cosmetic has great gaskets, when I just finished up with my rebuild I went with Namura gaskets and there ok but if you get them get a OEM base gasket cuz the Namura ones are junk.

For a high comp piston it all depends weather you wanna go with race gas or not I went with 11:1 to stay under so I dont have to go with race gas.