1995 9.9 hp fourstroke oil leak

[Jumbo3905]

I have a 1995 9.9 hp Johnson 4 stroke and it spits oil from the tube that runs on top of the carburetor from the cylinder head cover at the rear. Does anyone have any ideas why it would be doing this ? There may be a possible leak in the lower power head seal would it cause some kind of backpressure to spit oil out the cylinder head cover tube?

Any feedback appreciated.

thanks,
Dan

 

[boobie]

Re: 1995 9.9 hp fourstroke oil leak

Check the oil level in the crankcase and see if it's over filled, You may have other probs than a seal leak.

 

[Jumbo3905]

Re: 1995 9.9 hp fourstroke oil leak

Oil level is not overfilled low if anything. Everytime I crank over the engine manually there is oil spitting out of this tube, no idea why that might be, presumably there is oil in the cylinder head cover for lubrication but what would cause it to "pulse" out as the engine goes through it's four strokes?

 

[boobie]

Re: 1995 9.9 hp fourstroke oil leak

What's the compression on it ? Have you had the valve cover off to see if anything is wrong in there ??

 

[Jumbo3905]

Re: 1995 9.9 hp fourstroke oil leak

Haven't done compression test yet I need to find an adapter for a smaller spark plug hole. In order to remove the valve cover I need to remove the motor lower cowling which I haven't attempted yet but I guess that will be my next move.

 

[Haffiman]

Re: 1995 9.9 hp fourstroke oil leak

Being a 2 cylinder 4-stroke engine, both pistons goes up and down at the same time. When pistons goes down, the pressure created under the pistons in the crank case is relieved up to the head area and some out of the ventilation tube from cover to carb. If any oil in the tube, it will be blown out.
Remove the tube/hose and clean it properly on the inside. When re-installing, see to that it goes in an even and straight loop to the carb without any 'lock' that may collect oil.
Do the same with the valve cover.
If black sludge of oil is found in the head and valve area, run a 'cleaning oil'.
Change oil and filter and re-test.
I always used a semi-synthetic 15W-40 oil in those engines(Shell Nautilus) and not the SAE 30 'junk' oil!

 

[Jumbo3905]

Re: 1995 9.9 hp fourstroke oil leak

thanks for the response Haffiman, I'll have to take a close look at the valve area and see what's going on in there.

 

[Jumbo3905]

Hello, been back at this leak problem after a few years and have taken apart the cylinder head cover. It appears there is a rubber gasket that has been deformed (perhaps by the submersion to oil) that may be allowing oil into the breather portion of the head cover. I assume no oil is supposed to get in to that chamber and only pressure gasses that need to be vented out should. This head cover is a discontinued part by BRP. I was wondering if a can just make a new gasket myself and if anyone had experience with this and what kind of rubber gasket material i should use. appreciate any feedback.

 

[thumbnut]

Maybe use loctite 518..or try an automotive gasket maker.