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My mower suddenly revved up past throttle set speed then blew out a ball of black smoke and died. If allowed to sit for a bit it will start again, run a bit - enough to get the oil hot I would say - then repeat the cycle

I pulled the carb off and made sure there was nothing in it blocking it up and that the float was working and not filling with gas. I replaced the gaskets while I was about it. After reassembly, it did the same thing.

Does this engine have any electronics that might be overheating or vibrating loose?

I know only a little about engine repair.

TIA

aa

Black smoke is too much fuel in the combustion chamber and it's being burnt out in the exhaust.
Give us the Engine model number, being an Intek i think it's an Over Head Valve engine so the model number should be stamped onto the valve cover on front of the engine.

It is an OHV engine model number 128607 type 0113E1 code 040726PA.

Does that help?

I have suspected the carb but don't know if or how it can be adjusted. I have an inline shut off and run the carb dry after every use.

Does your carb have the primer bulb you press, or does it have a choke?
Both carbs appear to have no adjustments on them, if it's a choke type carburetor i would check too see that choke valve is staying open while running.

Sounds like a blown head gasket.

The carb has a primer bulb. Yes, I discovered when I took it off again that there is no accessable adjustment. There are seals over what I presume to be the adjustment screws. I removed the spark plug and it was carbonized and a bit oily but not burnt up.

That primer style carb has no adjustments.
i 2nd what fish said.
Try running the engine for as long as it will run good, and shut it down, then take out the oil dipstick, if you get whisps of smoke coming out, blown head gasket.