JLG40F engine question

[barklee]

alright so i ran into another snag in the gears. over the last 2 weeks i have been putting marvel mystery oil into each of the cylinder heads via spark plug hole. so today was the day i got the first reaction from the machine. i had a pry bar in on one of the flywheel teeth(not the best place but i work with what i got) and finally got some wiggle room.my dad actually has a vg4d not the vh4d and he said that it should be as difficult as it is to move the flywheel but i fell like if it isnt difficult then i run the risk of a blown head gasket? with his motor he said he can turn it with his fingers but then that shows lack of compression am i right? i cut a hole into the back of the chasis so the nut that is on the end of the camshaft can be accessed with a 1 5/8" deep socket hopefully i can get more movement throughout the cylinders. Im basically really trying to avoid tearing the heads off of this machine because of not wanting to pour money into it. i know this thread was not very productive but i want professional opinions. so please help me out

I cant really offer too much advise to your question but i have heard and witnessed that dumping transmission fluid down the cylinders is the best way to free up a frozen up motor. Good luck, those old Wisconsins are a real treat! When you do get her running make sure you have a full tune up kit with you at all times, points, condensor, cap, rotor, plugs (Champion D-21 only i believe, they burn hotter) and at least a spare plug wire. We had three or four of these motors in manlifts and couldnt get through a whole job without replacing plugs and points or rebuilding a carb.

 

[willie59]

I think I would at least pull the heads off the engine, I mean, it's a flat head after all, no valve train to deal with, and only need some head gaskets (relatively cheap) to put the head back on. After all, if it's seized in the cylinders, chances are the bore of the liners are going to be rough, maybe even have some rust rings. Once you get it to loosen up, if you do, with heads off, you could at least do some polishing of the jugs with some emery cloth.