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B48g pushing oil into the air cleaner

2K views 22 replies 13 participants last post by  bo2009 
#1 ·
What causes oil to end up in the air filer? I looked in to it slightly and found the breather mesh kinda squashed down but there's gotta be more to it than that. New to me machine with 2k hours on it starts ok but the oil in the filter is affecting the idle because I have to play with the choke to keep it from stalling . Any help is appreciated !! Thx!
 
#4 ·
Also check your oil level, if you are having carb overfill/rich running you may be getting fuel in your oil, which thins it out and raises its level.

Before anyone goes pulling the engine apart, first check crankcase vacuum.
 
#7 ·
is oil level too high?
can you remove the breather and check the reed valve?
 
#8 ·
FWIW, I had a similar situation with my P218G. I seem to recall the culprit was a leaky oil filter adapter gasket. Seeping oil at the adapter would get get blown up into the air cleaner housing by the flywheel. I replaced the adapter gasket, and no more oil in the air cleaner housing. YMMV.
 
#9 ·
I would check the o-ring on the underside of the dipstick cap. As Ron Haass correctly mentioned, if the oil dipstick is not sealed correctly when it is in the filler tube this problem can occur. Unfortunately, the problem you have can certainly mean more serious wear issues as noted by other members. Good luck. Joe S.
 
#11 ·
Boomer the oil level did look high but when it ran with out the air filter it looked like the oil mist was blowing straight out of the crankcase breather tube I change the oil over the weekend what is the oil charge for a b48g? I dont want to believe its rings I am not seeing any smoke while the engine is running I will do a compression test tomorrow thx for the responses
 
#14 ·
where the breather is located there is a plate and under it is a valve, you might have crud in the valve or a broken one
 
#17 ·
Your crank case is closed so when the piston goes up, it produces vacuum and when it comes down, it produces pressure. That pressure/vacuum cycle is the pulse that operates your fuel pump. you have a breather which has a one way check valve and a dip stick, which are the only two opening to the crank case. So if your dip stick has a bad o-ring or is loose, it disrupts the balance between the pressure/vacuum. I hope this makes sense.
 
#19 ·
Scott, The above is for a completely closed crank case whereas most single cylinder engines only rely on a breather with a check valve and much less pressure and vacuum. The dip stick doesn't have much if any affect on them. Now if blowy is bad enough, it will blow oil out the seals, dip stick and even the breather. Blow by is your pressure from the explosion above the piston getting passed the rings and pressurizing the crank case and thereby getting out wherever it can.
 
#21 ·
Ron great explanation as I did not understand vacuum side of things only pressure side of things. That being said I got a little time to run a compression test and came up with less than 50 psi on either side. That's a new one too me low compression but will start run and not smoke? Thx to all the responses. Looks like its time for a ring job!
 
#22 ·
Anyone have the correct number for the O-ring at the top of the dip stick tube for my B43G?? JD parts shows #0142 which cannot be correct.
Thanks
 
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