23hp Vanguard Oil leak Post 2.0

I posted a few days ago about my Vanguard oil leak. I had several replies/questions to the post but I didn't get any response to my answers, so I don't know what I did wrong. So here is version 2. The right side OVH cover has oil on it. Looks like the breather tube is cause of the leak? The top of the breather tube is attached with 2 bolts. The bolts were finger tight. I checked the oil and its perfect. The oil does smell of fuel. I pulled the plugs and they are black and smell of fuel. See attached, the left plug was actually darker and had more fuel on it than the right. Right plug represents right side of mower. I checked the compression, the right side is 125psi, and the left is 118psi. There is some dark smoke when the mower is started and the power does seem like its low compared to when I bought the mower.

All I have ever done to the mower is change the oil, oil filter, and plugs. The motor has 320hrs on it and I did the oil change at 300 hrs.

head gasket?
carb issues?
rings?

Any help would be greatly appreciated.

thanks

Wallers

What plug did you install when you changed the plugs. And are you sure it has the correct air filter. similar but incorrect plugs or air filter can cause your symptoms.

ILENGINE said:

What plug did you install when you changed the plugs. And are you sure it has the correct air filter. similar but incorrect plugs or air filter can cause your symptoms.

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When I replaced the filter I pulled the number off the filter I think. The plugs are a Champion RC12YC, but the new plugs I bought they other day are NGK.

Briggs calls for and from my own personal experience the RC12YC in the Vanguard will misfire. Requires the RC14YC which is a hotter plug. I use the NGK BKR5E here at the shop

If you have the heavy duty cyclonic filter which is part number 820263 you are probably fine. If you have the smaller round filter it should be part number 692519. There is a similar filter part number 694018 that looks identical but will cause rich running within about 2-3 hours of installation.

Both issues can lead to improper running, lack of power, and the misfire can cause gas to wash down the cylinder walls and dilute the oil which can cause the oil to be thinner, and also when the gas in the oil in the oil in the gas gets hot, it vaporizes and is pushed through the breather back into the intake, and will act rich running similar to if the choke was closed.

ILENGINE said:

Briggs calls for and from my own personal experience the RC12YC in the Vanguard will misfire. Requires the RC14YC which is a hotter plug. I use the NGK BKR5E here at the shop

If you have the heavy duty cyclonic filter which is part number 820263 you are probably fine. If you have the smaller round filter it should be part number 692519. There is a similar filter part number 694018 that looks identical but will cause rich running within about 2-3 hours of installation.

Both issues can lead to improper running, lack of power, and the misfire can cause gas to wash down the cylinder walls and dilute the oil which can cause the oil to be thinner, and also when the gas in the oil in the oil in the gas gets hot, it vaporizes and is pushed through the breather back into the intake, and will act rich running similar to if the choke was closed.

Click to expand...

Thanks for the feedback. I will check the plug and air filter part number when I get home.

So I checked the plug I bought and it's the plug you suggested, the plug cross reference is the champion I mentioned in the previous post. I don't know the part number of the air filter.

Wallers