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Discussion Starter · #1 · (Edited)
Hi Everone
I own a la 125 John Deere lawn tractor with 80 hrs on it…… its burning oil and smoking Plus leaking oil from the fuel pump……… I'm guessing its coming from the crankcase….. To much back pressure ??……When the oil is topped it smokes really bad then when it burns the oil to half it hardly smokes I'm hoping it only the fuel pump …plus how does the fuel pump run it has no wire or mechanical to run it ……I also did a compression test and it was 105 ..If anyone can help me with my problem that would be great
Thanks and have a great day
Cheers
Ed
Motor vehicle Automotive fuel system Automotive exterior Gas Automotive wheel system
 

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Welcome Ed! :)

Does the pump have three hoses connected to it? I would guess it to be a vacuum driven pump with one hose tied into the valve cover vent?

Have you noticed any gas getting into the oil?
 

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There should be something similar to a valve where the vacuum hose connects to the crankcase. My thought is that the valve is sticking or the diaphragm in the pump is bad. Like Mark asked, is there gas getting in the oil? If so, it may be the fuel pump and/or there is a blockage. Doesn't "sound" like a major problem.
 

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Discussion Starter · #4 ·
Welcome Ed! :)

Does the pump have three hoses connected to it? I would guess it to be a vacuum driven pump with one hose tied into the valve cover vent?

Have you noticed any gas getting into the oil?
hi mark
yes I have 3 hoses 1 to the carb 1 from the gas tank and one from the lower part of the oil filler tube I guess thats where the pulse comes from for the pump and vents the crankcase dont see any other hoses to vent the presser in the crankcase I dont think the gas is geting into the oil in the crankcase...... could it be my rings ? since the compression is at 105 any idea what the compression should be I used a car compression tester
any more info would be great
thanks
ed
 

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Discussion Starter · #5 ·
There should be something similar to a valve where the vacuum hose connects to the crankcase. My thought is that the valve is sticking or the diaphragm in the pump is bad. Like Mark asked, is there gas getting in the oil? If so, it may be the fuel pump and/or there is a blockage. Doesn't "sound" like a major problem.
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hi brad
Im thinking its the pump too....
I dont see any other hoses or valves I think the pump doubles as a crankcase vent too
also someone told me my its prob my rings because of my 105 compression what do you think?

thanks for the help
ed
 

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hi mark
yes I have 3 hoses 1 to the carb 1 from the gas tank and one from the lower part of the oil filler tube I guess thats where the pulse comes from for the pump and vents the crankcase dont see any other hoses to vent the presser in the crankcase
Not positive but doing some digging on the net you might still find another hose back to the intake manifold somewhere. I can't imagine them venting to air with the emission regulations today.

....could it be my rings ? since the compression is at 105 any idea what the compression should be I used a car compression tester
any more info would be great
thanks
ed
I would doubt rings. With only 80 hours I think odds would make that pretty unlikely. The compression release on the engine could make your readings low. Briggs recommends a leak down test instead.

Compression Reading | Frequently Asked Questions | Customer Support | Briggs & Stratton

Rather then rings I would give better odds to a head gasket or a check valve in a vent going into the intake manifold from somewhere on the top of the crankcase. I'm kind of doubting a fuel pump issue. If the pump had that much of a vacuum (or back pressure leak) I would think it would not supply the engine with enough fuel pressure to run. I suspect it may be oil just wicking/misting out of the tube connection due to being full of oil. If you do find another vent tub into the intake it will probably be full of oil as well and the main source of your blue smoke out the exhaust.
 
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