Odd oil leak

[ZSK]

I have a 2000 400ex bored to 440 with ross piston, HD rod, HD head studs and a few other little things. I blew 2 headgaskets then went with the HD studs. When doing that I replaced the base and head gaskets, but now I have an oil leak. It's below the cylinder so I know it's not the top end of the engine. The only places I can see would be the cam chain tensioner or the base gasket itself. Has anybody else had these leak before?

[speedy400]

be more specific on the leak spot, that would help tons, like if its the middle one where you would split the engine or on the side cases or what not, it might not the base gasket, btw, if there was a leak on the base gasket oil would come out of it.-darren

[ZSK]

It's right under the cam chain tensioner but I can't tell if it's that or the base gasket itself leaking. It's a good leak. About a quart came out in the last race which was an hour long.

[speedy400]

hmmm, you could try removing the cam chain tentioner and making sure that gasket is in good shape, I meen its fairly simple to take that off and check her out. but other then that I dont really know much about the base gasket, I've never had problems with it. good luck man.-darren

[ZSK]

The gasket is in good shape I replaced it when I took it off last time.

[440exnacsracer]

you did use a torque wrench correct? if you dont know if its the can chain tensioner, get some liquid gasket and put on both sides of the steel gasket and put it back on, sometimes you will have a little leak, but a quart in 1 hour. ....probably base gasket

[ZSK]

Yeah I used a torque wrench. Click type and went by the book.

[440exnacsracer]

hmmm got me thinking, could you get some pics? if you could get some close up, good detail pics, id bet money i could help
ben

[TC426EX]

hmm, by the cam chain tensioner huh... unfortunately my 426 motor is out of the frame right now and isnt here so I cant look at mine. If I remember correctly thats on the left side correct? If there oil there check the rubber seal that seals the wire s that go into the case for the stator etc... I had a small tear in mine and it wasnt sealing properly so there would be a little oil showing right at the base gasket where you are describing. Like I said, my motor isnt here right now, but if it is on the left side I would check that little rubber boot man...

[ZSK]

If you were sitting on the wheeler it would be the right side. Clutch side. I'll get some good pics later tonight.

[stupid driver]

right under the cam chain tensioner, hmm, heres a pic

[stupid driver]

its probably your base gasket. thats what i would first check

[ZSK]

Well I have some good news, it wasn't the base gasket. When I installed the tensioner I forgot to put the new gasket on:eek: The old one still sealed fine but a piece of my blown head gasket was on the gasket probably got on there while sitting on the bench. That piece wasn't allowing the gasket to fully seal leaving approx. a 1/32 of an inch gap. This was allowing a great deal of oil to come out. I removed the old gasket and put the fresh one on, buffed out the burr caused by metal. I raced a 3hr harescramble today and finished with the same amount of oil that I started with. Sounds like a fluke kinda thing. Thanks for the ideas.:macho