15 hp briggs vanguard problems

[pumper.atv 26]

Put a brand new briggs vanguard 15 hp on a lawn ranger. Using it in this minnesota winter put 5w-30 in it. Now that the temp came back up to the 20s, it starts blowing a little oil out the breather and into the carb (dumb design) could it be the thinner oil or what else. :banghead:

[W9JAB 156]

do a valve adj. and I think the problem will go away!

[pumper.atv 26]

practaly NOS motor. brand New but has been sitting on shelf for plenty of years :thumbs:

[pfrederi 18,379]

If engine had very little use rings may never have seated or could be stuck in their grooves. Leak down test will confirm/deny ring blowby...I am having similar problem with an overhauled motor in a Mule (M-274)

[Don1977 604]

I would think that the rings have not seated yet. The Vanguard has an oil pump and pressure lubrication. I run 10/30 in mine year around in the summer at start up I get

40 or so lbs. pressure that goes down to 29 lbs. after it warms up.. When it's cold ( 30 degree or below) at start up I get 60 lbs and it never get much below 40 Lbs. after it warms up. I had a break at the top in side cover gasket last summer, you would not believe how much oil it would pump out.

[pumper.atv 26]

so should i keep running it it only starts to blow oil once it is warmed up alot?

[rickv1957 73]

Run it for a while and see if there is an improvment or not,Rick

[Sparky-(Admin) 22,252]

If you decide to run it for awhile make sure to check the oil level constantly.

Mike......

[pumper.atv 26]

tried it again today started blowing oil quickly shut it down and i checked the oil it was way over and smelled of gas should i try a diff fuel pump because it works of of engine vacum in the head, i have a few avail. :WRS:

[Don1977 604]

If your oil smells like gas your carburetor float is sticking or set too high and allowing the gas to run in your crank case. You need to clean the carburetor and adjust the float it may be set too high. Then change your oil you don't want gas in the crank case.

[pumper.atv 26]

how would the gas run into the crankcase from the carb??? :thumbs:

[TT-(Moderator) 1,147]

Gravity. :thumbs:

[gwgdog66 23]

how would the gas run into the crankcase from the carb???

I've had this happen more times then I care to tell When the float sticks open (just a small spec of dirt gets in the needle and seat area, the float can't shut off the fuel) the excess fuel will enter the valve area and combustion chamber. What isn't burned off will seep into the crankcase. When you kill it gravity lets the excess fuel flow past the piston and the rings, through the cylinder, winding up in the crankcase with the oil.

[Horse Fanatic 50]

The elevated oil level can cause the blow by. When you fix your carb problem and change your oil, your problem might be solved.

[Cody 277]

This is a long shot but if your engine has a fuel pump it is most likely a vacume fuel pump. If the diaphram in the pump gets a small pin hloe in it the gas would run right into the crank case. I have had this problem on a few onans.

[pumper.atv 26]

took a fuel pump (vacuum) of one just sitting around, will try this first (had this happen before on a diff briggs) if this doesn't fix it i will try the carb :banghead:

[pumper.atv 26]

took the fuel pump off the problem motor and disasemmbled it, found gas on the vacuum side will get one this week and put it back together

[junkman 0]

:D my fuel pumps always blow open the needle and seat