New M274 mule owner

[Auto Shop teacher]

You might start with pulling the top cowling off to verify there are no rats nests in the left cylinder. Having done that I would suggest you hook up a mechanical oil pressure gauge to verify you aren't going to ruin your engine for lack of oil. I recall Chuck saying you want about 30+ psi showing on the gauge. Once cooling and oil pressure are checked, it probably will be a fuel issue (probably), or spark issue (not as likely) as some coils fail when hot. The spark issue requires you testing for spark right after the engine cuts off, so I would suggest you start with fuel flow and pressure first.

Hopefully someone with some real world mule experiences will throw other ideas they have found. If nothing else, you will know what it isn't, but don't rush as you may miss something. (Been there, done that, and wasted lots of time doing so. ) Good luck and let us know.

[Chuck W.]

One quick check for oil pressure is to take the oil line loose where it goes into the governor and then crank the engine. You should have a good stream of oil coming out of this line. If not, your oil pump may have lost it's prime, happens when the engine is upside-down, oil drains out of the "pocket" in the oil pump. Make sure you pre-fill your oil filter canister with clean oil. Here's my thread on oil pumps:
viewtopic.php?f=79&t=142731&p=823087&hi ... re#p823087

As far as the fuel tank, the RedKote does a good job of sealing tiny pinholes, but if the holes are big enough to see, the sealer will run right through them and won't seal. I have a friend who recently took an old, rusted out fuel tank that I gave him and had a welding shop install a new bottom. It looks great, but I think the price was approaching the cost of a new tank!

[cpearce]

It has a bad oil leak into the exhaust pipe on the fan side . What would cause that?

[Auto Shop teacher]

Chuck, thanks for the great link, could you put it at the top with your mule repair series, as there is good information all of us can use.

[cpearce]

It is not primed so ill do that now but I'm not sure what to do about the leak? Could the cylinder have gotten damaged?

[cpearce]

How much oil goes in the air filter?

[Auto Shop teacher]

Chuck is talking about priming the OIL filter, the air filter is a dry element. If you have oil INSIDE the exhaust pipe, on any engine that means oil is getting into the cylinders. The main source of that would be blowby on the piston rings, the other source is oil leaking between the valve stem and valve guides like the old 350 Chevys had a problem with #8 cyl fouling the spark plug. Pull out the spark plug and see if it has oil on it, or oil ash. Oil outside the exhaust pipe = oil leak.

[cpearce]

Would mine not be an oil bath air filter? The air filter was full of oil when I got it.

[Chuck W.]

Yes, pre-fill the ENGINE OIL FILTER, not the air cleaner element, it's a dry element!

Are you talking about an external oil leak that is dripping onto the exhaust pipe or oil actually leaking INTO the exhaust pipe? If it's an external leak, check the fitting on the oil drain tube where it enters the rocker box, it is VERY easy to crack the head in this area. This is not a pressure line and only needs to be snug, overtighten it and you'll crack the head.


You could also have damaged O-rings on the push-rod tubes causing external leaks, or a leaking valve cover gasket, or the rubber plugs for the head bolt access could be leaking/missing.

If it's actually dumping oil INTO the exhaust pipe, you've got valve and guide problems like Shop Teacher said.

[Chuck W.]

Would mine not be an oil bath air filter? The air filter was full of oil when I got it.

Unless somebody's put a different air cleaner on it. All 2-cylinder mules used a dry element in the air cleaner.

The crankcase vent line ties into the air filter housing and when your engine lost a piston, it may have forced the engine oil through the crankcase vent line and into the air filter housing, but normally, there should be NO oil in the air filter.

[Auto Shop teacher]

Great photo there Chuck, really illustrates what you are talking about. If your air filter housing is full of oil, isn't the only place to get that much oil is blowby from the rings?

[cpearce]

I'm pretty sure all my issues are coming from oil in the air cleaner. The carb would have sucked it in and spit in with the gas and hence it went into the exhaust. Probably also the reason it's hard to start and keep running. I'll let the filter dry out and try it again this afternoon.

[Auto Shop teacher]

If your filter is soaked in oil that would be like running with the choke on, starving the engine for air. You might want to look at the spark plugs to see if they are black and sooty, which is a clear indication of too much fuel. If that is the case, clean, dry, or replace the plugs as they could be wet and may not spark and try running the engine with the air filter off for awhile to see if that is your problem.

[Auto Shop teacher]

If you can keep your engine running again without the air filter, you can clean out all oil out of the interior of the air filter housing and try running the engine with the housing on for awhile. If you get oil in there again, you have a blowby issue which normally would mean a tired engine.

[cpearce]

Works much better now. I keep running it in short increments as I'm nervous about it still. Didn't notice oil back in the filter yet. I've learned its much easier to start by pushing it downhill and popping the clutch. I'm hoping the oil everywhere is from the filter and just needs to burn off. I guess time will tell.