new 426 leaking gasket...?

[AtvKid4Eva]

hey guys we just build my brothers 400ex with a 11:1 426 piston and a stage II hotcam..well we got everything together and i torqued everything to spec per the honda manual and used cometic gaskets..the bike also has GT Thunder Head studs..so ive just noticed what looks like the base gasket leaking and then i also noticed the cam chain tensioner gasket leaking...so im thinking that the oil leaking from the tensioner gasket could be running down the base gasket making it look like its leaking? has that happened to anyone? we r gonna replace the tensioner gasket soon and see if that solves the leak..if the base gasket is slightly leaking would this really hurt anything on the motor? IF it is leaking at the base gasket it is a tiny tiny leak..let me know your input guys. ive never seen a base gasket leak before and ive built several 400's. let me know what u guys think thanks!

[DragonGunner]

Your on the right track, replace the cam chain tensioner gasket an see what happens....I've had problems with head gaskets but not the base gasket. A little oil leaking won't hurt, you would just have to keep an eye out on the oil level over time...just aggrevating an not clean.

[CJM]

Replace the cam tensioner gasket and clean it off and take it from there.

If the base gaskets leaking after that then replace it.

[AtvKid4Eva]

im 100% sure the tensioner gasket is leaking. also if the base gasket is leaking what would have caused this?? i torqued the bolts right i'm sure of it.

[CJM]

If the base gaskets leaking it can only be from a bad gasket or the head/block is warped-but I doubt it.

[AtvKid4Eva]

if we do find it is leaking it has to just be a bad gasket..doubt anything is warped. thanks guys!

[sixer3]

I always spray my base gaskets with that copper perma-tex spray gasket stuff. never leaks

[2001400exrida]

it ain't gonna hurt nothing to have a small head gasket leak. the main thing you want to watch out for is that base gasket.

[AtvKid4Eva]

the head gasket is fine. if anything its the base gasket.

[sixer3]

i think he meant to switch those two terms around...haha, and if so he's right.

won't hurt anything to have a little base gasket leak however you do not want your head gasket to leak

[AtvKid4Eva]

lol yeah i think thats what he meant...thats what i figured. i got the tensioner gasket today so we will see.

[rubbersdown]

Originally posted by sixer3
I always spray my base gaskets with that copper perma-tex spray gasket stuff. never leaks

I use copper gasket maker on all of my paper gaskets. A thin coat on each side will do ya, I cant even think of the last time I had a gasket leak.

[AtvKid4Eva]

yeah, but i dont see why it would need an additional sealer added to it? a gasket meant for the application shouldnt need gasket sealer added to it for it to seal..just my thought.

[rubbersdown]

Originally posted by AtvKid4Eva
yeah, but i dont see why it would need an additional sealer added to it? a gasket meant for the application shouldnt need gasket sealer added to it for it to seal..just my thought. Not usually, especially if the motor is relatively new, but after 5 or 10 rebuilds and the cases being split over and over you get little nicks and scratches in the mating surfaces that can cause leaks with a paper gasket and the copper gasket maker helps fill those little imperfections in. I just take a little bit (about 1/2 as much toothpaste as you would put on a toothbrush) and put it on the tip of a q-tip and spread it on the mating surface of both sides. like this pic of my last build a couple months ago...http://i31.photobucket.com/albums/c368/rubbersdown/DSCN3373.jpg

[jensenracing77]

what brand of gaskets did you use? i have had several problems with the wiseco brand gasket sets. i have had 3 400Ex engines leak at the t chain tentioner with there gaskets. they look good but just don't seal. another local ATV shop has had the same thing happen with there gasket sets for the 450ER.

[AtvKid4Eva]

we used cometic gaskets...the cam chain tensioner was taken off several times and reinstalled and the stock gasket was never replaced so it has an excuse to be leaking lol. i had one cut for the tensioner at the local honda dealer. should get it installed tomarrow.

[AtvKid4Eva]

so does it hurt anything if you just reinstall the tensioner without relieveing the tension by turning the little flat screw in the back?

[rubbersdown]

Originally posted by AtvKid4Eva
so does it hurt anything if you just reinstall the tensioner without relieveing the tension by turning the little flat screw in the back? ACCT's are spring loaded and only provide the amount of tension thats needed, if you just put it back in without bringing the adjusting "foot" in, your cam chain will probably be to tight and can case wear on your cam and bearings. Screw the "foot" all the way and it will lock in place, install it, then when your cam and everything is in just slowly release the "foot."

[togup]

Originally posted by rubbersdown
Not usually, especially if the motor is relatively new, but after 5 or 10 rebuilds and the cases being split over and over you get little nicks and scratches in the mating surfaces that can cause leaks with a paper gasket and the copper gasket maker helps fill those little imperfections in. I just take a little bit (about 1/2 as much toothpaste as you would put on a toothbrush) and put it on the tip of a q-tip and spread it on the mating surface of both sides. like this pic of my last build a couple months ago...http://i31.photobucket.com/albums/c368/rubbersdown/DSCN3373.jpg

I agree ,I think the most over looked part of a rebuild is the mating surfaces you got your new cam or piston in and you cant wait to get it together and you sling it together and it leaks. these motors have very small mating surfaces so you got to look them over good and never pry them apart when disassembleing them you leave gouges . next build run your finger nail across where the gasket goes youll be surprised.

[AtvKid4Eva]

i made sure all the surfaces were smooth and i removed any old gasket and smoothed down anything rough theres no reason that base gasket should be leaking if it is besides a bad gasket.