Gas in oil Max iv 01 18 hp briggs

[warpony1]

Had gas in oil so bought a new carb and put it on and still getting
Gas in oil??????

[racerone3]

I would start by replacing the fuel pump. It is a diaphram pump which uses crankcase pressure to work. If the diaphram goes bad, it can backfeed fuel back into the case

[MAX IV Mark]

When I was looking at the Briggs and Straton website I saw something I never thought about. The new machines have gas shutoffs built into the kill switch on the engine. They said that if you trailer equipment alot the vibration caused gas to leak by the float and shortens the life of your engine. Probably not related to your problem, but good to know that there is a good reason to turn the gas off when you put your machine on a trailer.

[LarryW]

Max IV Mark,
Is the gas shut off your talking about the same thing as the anti backfire solenoid that's mounted in the float bowl? If so they have been around for a while. Not sure specifically for max but I had a 89 riding lawn mower with one in it. It was a vertical shaft 14hp vanguard twin. Unless it was a 98? I might have the year mixed up but either way I guess.

[MAX IV Mark]

Here is the propaganda footage I was talking about. Even if stuff like this has been around for 15-20 years..... lots of these machines are older than that. A backfire solenoid only shuts off the idle passage I believe and it can still leak fuel through a main jet (at least that was how my air cooled VW was)

[warpony1]

Max iv 18 hp Briggs still oil in gas

New carb new fuel pump new coil new solenoid
New plugs. I own a Argo that puts this wheeler
To shame. They don't sell these for 13 g and have
Power like this. This 2001 max cannot get out of
It's own way!!!!! Some max guy out there must
Know???????Please just totally did whole restoration
Chains spockits painted frame all new bearins in and
Out. The nickel and dimes must stop.
Warpony1

[Bazooo guy]

Put a fuel shutoff like this one at the carb.
Inline Fuel Shut-Off Valve for Small Engines| Shop BriggsAndStratton.com

Change the oil and use the shutoff when its not running.
Check the oil again after you dirve for a bit.
Shouldnt be gas in the oil if there is the engine could be running rich and fuel is blowing past the rings.

[warpony1]

Have one already in line I use it all the time every time I
Stop it on trail every time it goes in for the night...I'm going
To adjust valves tomorrow I hope this will stop gas in the oil
And plus give it some power
Jonny B

[Bazooo guy]

A compression test would tell if the rings are bad.
Do a dry test then squirt some oil in the cylinder and check it again.
If the compression goes up the rings are leaking.

[Radicalrescue]

i would check your gas cap,pull ur fuel line blow back in to the tank u should hear air come out of the cap .i have a fork lift that did the same thing hope that helps

[warpony1]

Got a aftermarket cap with nice hole in it for it to breath
Gas sqirts out all the time a little drible.
Jonny B

[warpony1]

I was told you can't check compression on a ohv twin because
It base a compression release on the Engine.
Jonny B

[Bazooo guy]

You can still do a compression test but the #s will be lower than when its running.
Insert compression gauge in one cylinder and crank engine over until theres no further increase in pressure.
Repeat on the other cylinder and record that reading.
The difference between both cylinders should not exceed 25%. More than 25% indicates loss of compression in the cylinder with lower pressure. Squirt a bit of oil in each cylinder and test them again. If the numbers are higher the rings are worn.
From 50 to 75 lbs. will run but be low on power, 75 lbs. and up is good.