Got myself wondering why the oil leak? My 35 vanny only has 5 hours on it and I went ride in the delta yesterday for a couple hours. Motor ran fine most of the day.... At one point it starting loosing rpms quikly and killed..... Thought it was out of fuel so we swapped tanks and it ran fine. When I got back to the launch I noticed oil running down the side of the motor that came from the crank case gasket. Ive heard of this problem with motors with aftermarket cams and motors with alot of hours.... I only have 5 hours w/ heads, mikuni carb, evt intake and marshmellow exhaust. What should I do?

Check your case bolts and make sure they are tight.

Yeah.... Thats why I posted today, cuz I'm at work tonight and I plan on play with it in the morning and cleaning up the oil then go ride around my house and see if it happens again. Looking for ideas to try in the AM! I just dont understand why it would do that if that seal on the gasket has never been broken and the motor only has 5 hours!

Welcome to the world of mod's. Warren Cooco has found less problems with leaks and bolts coming loose with the change to 3 blade props. They run with less vibration. Have some one check your prop for balance and vibration.

When you start turning more rpm or more dia. even a little out is too much.

JD

When my motor was stock it had that same leak twice,its just a common problem with them.

My stock motor is leaking... Its a Briggs thing... I'm leaking starboard side near the serial number about even with the starboard exhaust port on the seal. its a slow leak nothing "dripping" all my bolts are tight too. Just going to take care of it during the split.

When I rebuilt my motor, I got the latest gasket from GD. If I remember it was metal, I also used some loctite # 518 to seal the casket. They use that in oilfield pump work great stuff very expensive. Degrease every thing, let it cure before starting the motor. Pay special attention where the oil passage is. Degrease bolt hole, use locktite , studs are better than bolts if you can get them. Get a dual pitch stud if possible. I went back with bolts because of time problems and have not had problems yet. Use a torque wrench.

JD

Iv not had a gasket EVT or stock last over a few hours.....i did start leaking on the frst evt gasket and i stoped it with removing the bolts and replacing them with red lock.

good luck.

2 stock and 2 after market gaskets that leaked

This may help.


viewtopic.php?f=3&t=3987&hilit=bushing

I have 200 hrs. and my stock gasket and it is starting to leak.
hopefully it can wait till after the season to tear it down and fix the problem.
basinlover seems to have a good solution to the problem.

Its all about vibration control and keeping the bolts tight, metal gasket is better than fiber, pay special attention where the oil channel is, use the loctite.

JD

My stock gasket didnt last. Got the EVT gasket and worked great. Bolts kept breaking though. Talked to Silkpower and we decided I should try ARP studs and go back with factory gasket "just for kicks". Well Tuesday night when I tore it down I found my EVT gasket was broke "failed". BUT IT DIDNT LEAK!!

the case gaskets leak because of bad engineering.

mine is starting to leak, and the motors only got 550 or so hrs.

they usually start leaking at 75 or so hrs for me. and mines all stock.