Broken camshaft gear on a Confidant EZT750

This is a case of very poor engineering using materials that will fail. Constant overheating due to a very dirty engine has also compromised the head gaskets.
 
This is a case of very poor engineering using materials that will fail. Constant overheating due to a very dirty engine has also compromised the head gaskets.
I don't completely disagree. New engines are not like the old flatheads. However, I think that if this engine hadn't overheated, and had been properly maintained, this wouldn't have happened, and it would still be running just fine. The crank (with rods & pistons connected) turns over smoothly, and the cylinders still have cross hatching. I don't think either of the head gaskets blew. They are the newer style. I'm replacing them anyway, and every other gasket and seal I can access.
 
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I finally got this engine back together. It was a pain. After having the thing apart, on my bench for a week, while the camshaft was being delivered, I noticed that the governor gear was damaged. And then I noticed the oil pump gear was damaged, too. So I ordered those, and had to wait longer to get all the parts. It's finally back together, and running great. Just in time for mowing season. Actually, I was a bit late getting it fixed. I had to do one mow with my old mower. My wife is happy, too. She enjoys mowing, but only with this machine.

Now... if I FINALLY got everything fixed, this thing should outlive us both.
 
These are air cooled mostly with some oil cooling. We all must keep the cooling fins clean and clear like a new engine block. If not look for engine damage like this.

Cooling fin cleaning is in EVERY engine manual out there minus the water cooled ones. A yearly must do or more often. Download your engine manual and read it.
 
Hi Slomo,

Air flow on an air-cooled engine is commonly misunderstood.

I'm sure you have seen the ones where the customer would take off all the shields so the engine could "cool better". Worse yet is some idiot at a shop that believes that nonsense.

They were too much trouble, so why bother putting them back?

After a couple of head gaskets fail prematurely, they might figure it out, or the engine is too far gone to save by then.

After 50 years as a technician, I have learned to accept that small engine equipment is not designed to be "idiot proof".
 
Please explain what exactly was this overheating issue and how was it repaired?
The cooling fins were almost completely clogged with oily dirt. I bought the mower, fixed a few things that HAD to be fixed, then used it for a half season. During the off season, I did a more thorough service on it, and found the clogged fins. I had the engine off, so I cleaned the fins really well. It ran for almost two more seasons, so I thought I'd dodged the bullet.
 
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