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Discussion Starter · #1 ·
Shortly after posting about the gear box on my Craftsman garden tractor Model 917.255980, I went ahead and purchased the used Craftsman garden tractor Model 917.255950. To recap, my xx80 has a vertical shaft but had some gear box problems and the steering gear needed to be rebuilt. I was leery to buy the xx50 because it had a vertical shaft requiring more pulleys etc. But I could interchange the gear box as well as the steering column, so I bought it for parts, if nothing else.
I didn't get much chance to use it before the week long rain came. It finally dried out enough to use, so I've been moving firewood with it and my 5x8 trailer. I was tickled pink to have a reliable tractor again (with solid steering and all its gears). I mowed a small section of my yard with it and no problems. I was thinking it was in better shape than my xx80.
Well today, I decided to tackle the section of yard that hadn't been mowed in a while (ca 6") due to mower problems. After about an hour, I noticed the engine felt really hot and then it started to smoke. I shut it off and waited a few minutes. It started right up so I continued to mow. But it started to cut out again so I got it back to the garage before it died. Some debris had fallen onto the engine and it was hot enough to smoke. Once the engine cooled down after 30 minutes, it fired right up so I got it into the garage.
Hi had checked the oil level when I bought it and when I got it back into the garage...it was fine.
Any ideas on what could have caused it?
P.S. Sorry for the long post, but I wanted to include everything I knew about it so you wouldn't be asking questions that need not be asked to speed things up.
 

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I'd pull the engine cover(s) and look closely at the cooling fins to confirm none of them are clogged.

You mentioned that you were mowing when the engine began overheating and also the grass was extra tall. Was the engine bogging down while cutting it? Could it have been the engine was simply working on overload due to the tall grass?

If the cooling fins are clean and the tall grass wasn't the issue, then I would have a close look at the pulleys and PTO when the key is off. One of the pulleys or the PTO could have an issue and be tight causing the engine to work harder to overcome the force.
 

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:ditto: Also if your not already doing so keep the throttle full up in the fast position. Under full load the higher rpms will keep the fan moving more cooling air. Also in real tall grass keeping it lugged down continuously to a near stall is not good as once again cooling air flow decreases. I usually cut higher and make more then one pass or only take a partial width cut each pass as well as intermittently moving into the cut areas to grind up the excess which gives it some time to run at normal rpm and unload the heat buildup.

What was the air temp while you were doing the mowing?
 

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Discussion Starter · #4 ·
I thought about the pulleys and PTO, but wouldn't I smell rubber burning from the belts dragging?

The Temp was around 65 F, and I mowed the taller grass at a lower (slower) gear speed so the engine wouldn't bog down and I would get a clean cut.

This Horizontal shaft (xx50) engine does have a lot of extra metal shrouds around it. I might remove as many as I can (and check the fins).

Also, I might as well check all pulleys (deck as well) for any issuse.
 

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Make sure to reinstall the tins! They are designed to let air flow to maximize cooling, somewhat different in our heads that it needs open to cool! Made that mistake once!
How long has this engine sat? Possible smoke from collecting dust! We get that a lot with ours as we buy mainly non runners.
 

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rodents like to build there nest inside the engine, if stored outside you should check them at the beginning of the season while doing the yearly maintenance
 
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