440ex Problems...please help!!!

[416exfreak]

Well, I rebuilt my 440 this past July...roughly 6-8 months ago. I ordered the "scary fast" big bore kit froma company in DirtWheels.
It consisted of a new sleeve, piston, rev box, cam and all the gaskets.

Well, it has been going downhill since it got put together. Now it wont pull 5th gear and is losing compression badly. Im going to rebuild it again within the month, and im wondering what things i shoudl get to prevent this from happenening again.

It has 12:5:1 compression, a stage 2 hotcam and a fresh valve job.

Do I need to get the heavy duty head studs from GT Thunder, maybe a valve shim kit or anything else?...anyone who has a 440, let me know what youve done to your engine to make it hold together....any help will be greatly appreciated!:)

Thanks in advance
Justin

[416exfreak]

Come on....someone has to have some input!!!:ermm:

BTW: it is spreading apart between the cylinder and the head! Thats where im losing my compression! :scary:

[quad71]

Get the studs a must have.

[Ruby Soho]

get the gt thunder studs.. i bought a wiseco 440 with 2 hours on it, rode it for about 2 months and blew a head gasket, the head stud's nut was only hand tight because the stud backed out (i didnt know this yet) so then i replaced the gasket. 3 months later i blew another one. i read up on it and found out getting the HD studs is a must!!! i had them installed and used a honda factory gasket and its holding up good so far. thats the only problem ive had with it, everything else is fine

[mod440ex]

i have had my 440 kit for about 2 years, and i havnt had to do anything to the head gasket, i do have heavy duty studs i would just try new rings, and make sure that you break it in correctly. i rode mine around in the woods up and down in throttle and shutting it off to cool off regularly, also what type of fuel are you running, you will should run a mix of 50/50 race gas and high octane pump gas. you might think about a valve job and port and polish the head, well woth it.

[CDCHONDAS]

400ex doesnt have valve shims or anywhere to put them, they are for overhead cam engines ex. 450r yami 450 z400

[416exfreak]

I run c12 in it most of the time, that or U4....the head will be getting ported and polished. and it will be getting new rings too.

[Ruby Soho]

get studs too:macho

[416exfreak]

Originally posted by Ruby Soho
get studs too:macho

FO SHO!!!!!!!!:D

[79400ex]

I have had several 440 egines. I have only blown one head gasket and that was because the oiler cooler got plugged. also I ran it that way for several races. I have never to add the HD stud any of my egines. Since you are already having touble go with the HD studs and much sure you troque the studs and head to wright amount.