Hi, I think my Craftsman riding mower (16.5HP electric start) has a blown head gasket or worse. The engine can be turned with no resistance (I don't have a compression tester but I can tell there's no compression). I notice that oil is leaking when the engine is turning over, right behind the starter on the side of the block. I was wondering if this is symptomatic of a blown head gasket? I can't tell if that is where the head mounts to the block, but it looks like there is a seam there.

Here's what happened: When I was mowing my grass on a 40degee incline the mower made a metallic sound and stalled. I pushed it to level ground and when I tried to start it, the electric starter clicked and couldn't turn the engine over. I checked the oil and it was a little low and dirty, so I changed it. After changing the oil, the starter still could not turn the engine over, so I pulled off the top cover and manually turned the crankshaft by holding the top cooling mesh by rotating it back and forth till it finally came free. It was stuck. Once free, the starter would turn the engine over - but it wouldn't start. It just cranks away. I can turn it by hand and it does not feel like there is any compression because the engine turns with no resistance. Then I noticed an oil leak on the side of the engine, right behind the starter. The oil leaks when I turn the engine over with the electric starter.

So my question is whether a blown head gasket would cause this kind of symptom? I guess it could be a busted shaft too, but the engine doesn't have any grinding or banging noise. Is there a pin or something like that? Is there any weblink to get a repair manual for cheap?I'm not too motivated to tear it apart unless the problem is something simple like a gasket. If the shaft is broken I suppose the fix is to replace the engine?

Thankfully this tractor was given to me by a friend who retired. It 'was' about 6yrs old (I'm not optimistic). I have real bad arthritis in my knees so I was really beginning to like the tractor. Had to use the push mower after the incident and now I'm sitting with Ice on my swollen knee.

Anyway, thanks to anyone who would care to give me some opinion on the problem. I think I'm on the right track but not an expert on small engines.

I would say definitely not the head gasket. Sounds a lot more like a broken connecting rod. The fact that it would not turn over initially until you rotated the shaft tells me there was a mechanically broken part. Manuals are available from the manufactures site of most engines. Not sure which one you have, but Briggs :Manuals, Parts Lists, & Wiring Diagrams - Briggs & Stratton (http://www.briggsandstratton.com/display/router.asp?docid=78484)
Or Kohler:Service & Owners Manuals - Service & Support - Kohler Engines (http://www.kohlerengines.com/service/manuals/index.jsp)
And Tecumseh:Tecumseh Power Company (http://www.tecumsehpower.com/frameset.php?page=CustomerService/index.php)



Good Luck,
Morrowrj

Thanks for your reply and the links. I was thinking that I might pull the sparkplug today and then look into the head with a flashlight while rotating the engine by hand. If the piston is not moving I suppose this would confirm the theory of a broken rod?

Yes, the con rod usually comes through behind the starter. Getr a flash light and look close.

Don

Yeah I had one do that. It slug a rod and broke through the crankcase. That probably where the oil is coming from.