MM ZA

Just bought my first MM and want to paint it but I have an oil leak I can't seem to stop. Its coming out from the crack between the two heads on the left side. I tightened all the head bolts and it still leaks. I notice that there is a little crack between the block and the head for about an inch at the front of the rear head. Anyone care to guess whether its a head problem, a block problem or will a head gasket fix it?

I would like to know what the torque on the head bolts are supposed to be and also the intake and exhaust valve clearance please. Are the bolts that hold the rocker arms down the same torque as the headbolts on the right side? Trying to paint this thing and get it to a show next week-end. Many thanks, Sonny

The bolts that hold the blocks to the case do not have a torque specified. I would suggest that you torque them to 15ft. lbs. They just hold the blocks too the case and there is only a thing cork gasket that you sealing against.

One thing - if you go to change the head gasket - you have to loosen the bolts that hold the blocks down to the case.

Tighten the head bolts in a stage of 3 - like 20ft.lbs., then 35ft. lbs. then final torque.

also, you need to go from the center outward in torquing the thing. After you have run the tractor and had it hot - and it has cooled - go back and retorque it.

As for your oil leak - not sure what you are referring too. However - if it is a seeping crack in the casting and not leaking under pressure - a little "JB Weld" or other metal putty would probably stop it.

Remember - the "head" is on the left with the spark plugs in it. The "blocks" have the valves and make up the cylinder bores, the "case" is where the crankshaft is. This little engines are a little non-traditional in design.

If you are leaking between the blocks - then you probably have a bad block base gasket - and the only way to fix that is to pull the blocks off the tractor - this involves removing the rod bearings and a whole bunch of other work that you may not want to get into at this time.

My suggestion to you is to seal that crack - if th oil is coming from there as I advised - Get ya a can of starting fluid - ether - and spray down the area to get all of the oil residue off. (the ethere evaporates and leaves no residues) Then you can paint it and be on your way.

If you can live with the leak - then wait until you have some major repair work to do before you go and tear into it.

Phil

The oil leak, it is coming out from the center of the two blocks, if thats what they're called, on the left side of the engine. Not on the spark plug side. I call that the right side, which I determine by sitting behind the steering wheel.

The crack I mentioned is at the front of the rear block for about an inch where it looks like the left front of the block dosen't fit down on the case like it should in that one inch. Now, if I try J B Weld I might not stop it if the leak is coming from further in there between the blocks where you can't see its origination. Whatayathink? I thought maybe the left front of the block is warped there and not sealing and allowing the oil to seep out when it runs. I tightened the bolts after my first post but it still leaks. Thanks again, Sonny

It is my opinion that a part of the gasket that seals the block to the engine case is missing - since the oil is under pressure - it will leak. You can pull the valve cover off and you will see the oil line (copper tube) that I am talking about and where it meets the case. Again, without seeing the tractor - I can't be 100% but I think that is what the problem is. The only way to fix that is to replace the gaskets. - or lift the blocks up some and smear RTV between the surfaces and try to seal it up.

That would be the easiest way - unless you want to pull it apart and replace all the gaskets. You can pull the blocks/head/mainifolds/water pump off as an assembly. You'll have to pull the side cover off on the left side of the engine, all the water hoses, electrical wires, radiator, air cleaner, gas tank, etc. - and then pull the caps off of the connecting rods to lift the rods/pistons from the crank with the blocks. This is not a hard job - but time consuming. Then you can replace the base gaskets.

Phil

From this info I can go back to it, take a last good look then decide what to do. You have cleared up a lot for me. I'm in Florida, come on down and I'll buy you lunch. That gasket could very well have a piece deteriated and fell out because I think the bolts were quite loose. Thats not a cork gasket though, is it?

Sonny