Thanks for reading. I have a JD LA105 with a 19.5 single cylinder OHV. Replaced the head gasket, common cause, the mower starts and runs great but after a minute or two it starts bleeding oil out the fuel pump and breather tube. Wispy smoke when I pull the dip stick too. I adjusted the valves after the head gasket, took the fly wheel off and checked the valve which looked fine but there was no hole for oil to return to the crankcase. I am hesitant to tear it down for rings because it runs great otherwise. The mower has 180hrs. Anything else that can build pressure like that? Oil is slightly low from having come out and no fuel smell
Hammermechanicman
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The head gasket is blown. Seen it blow oil out of the fuel pump a few times.
Craftsman Garage
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Ditto, blown head gasket, although, sometimes i see that wispy smoke on engines with good head gaskets, specifically briggs vtwins. Anyway, I'm not sure that that engine is supposed to have a fuel pump, usually those singles dont.
Some of the Intek singles have a fuel pump. It is located on the left rear corner of the engine and powered by a pulse line coming off of the dipstick tube.
I agree, i did replace the head gasket and it was blown but I still am having the issue. I changed the fuel/pulse lines to the fuel pump and checked the breather but I still have crankcase pressure evident from the fuel pump leaking oil and the breather blowing off the air intake, especially under load but after cooling down it fires right up and takes a few minutes to build pressure.
Again, I did pull the flywheel and checked the breather valve too. In my mind I am thinking something else is contributing to the increased pressure like exhaust but I checked that too
Again, I did pull the flywheel and checked the breather valve too. In my mind I am thinking something else is contributing to the increased pressure like exhaust but I checked that too
Hammermechanicman
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A leakdown test would tell you more.
If the head was warped the new gasket could have failed on startup. Does it start right up but blows a puff of smoke the runs fine with no smoke? A slightly blown head gasket on that engine will do that.
If the head was warped the new gasket could have failed on startup. Does it start right up but blows a puff of smoke the runs fine with no smoke? A slightly blown head gasket on that engine will do that.
With the breather hose blowing off of the air intake makes me wonder if the orifice in the air intake is clogged. Some of those engine in were the breather hose connects to the air cleaner elbow has a dome shaped insert that presses into the air intake and which the breather hose actually presses over to hold it in place. Sometimes when the breather hose comes off the orifice will come out with the Hose. If for some reason the hole in that dome insert is plugged would also cause your issues.
I like that idea. I checked the reed valve on the engine but didnt look close at the air filter housing. The hose was blowing off the housing and I put a hose clamp on it (stupid). I have similar engines for parts. Thanks! I will let you know. I find it odd that it run so good but still has the pressure issue. What’s the likely hood that it run great with worn rings or warped head? Never did a leak down test and I was fixing it for a neighbor. At first it was a mouse nest packrd in the shroud and a chewed coil. Then it was a valve adjustment, new oil, filters. Started up good and ran so I gave it back. Then he said it was doing the oil thing and smoking, so I changed the head gasket and re adjusted the valves. That’s the backstory
No smoke until it runs for a bit and I engage the PTO
Hammermechanicman
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How fast does fresh oil turn black? A blown head gasket will turn oil black in a couple of hours of running.