Engine Motor will turn over and run but will not restart after mowing the yard.

After checking spark, coil, and fuel as you other mechanics suggested, I would run a
compression check first cold, then after it gets hot to compare. Could be the
valves have enough clearance when cold to start. But when heated up, they lose
clearance and come off their seats and not enough compression to start until
they cool down and the valve clearance returns and the valves return to their
seats.

I had an MTD for about 20 years with a Briggs and Stratton that did that. I just had to keep it running the whole mow, it had a parking brake thank god. after awhile I had too adjust the choke and throttle at the same time to keep it running with the PTO / mower engaged. I have no idea what caused this, I bought a huge starter, giant battery cables and threw in some hardcore 30HD. cleaned plugs filters etc. It ran, not much better than before, but then I tightened the choke and throttle with bicycle brake wire and it ran much better.

I have a Poulan chainsaw that starts once in a while and if stopped will not start
I have no clue. It has a lot of use though. SO DO AS I DO: FILL WHILE IT IS RUNNING OR TAKE TO A DEALERSHIP.
either way it's $$

bertsmobile1 said:

Needing to pull the choke on to get clean running indicates a lean fuel situation in the engine.
This can be an air leak anywhere after the emulsion tube ( brass tube which sticks up in the carb.)
A low float level in the carb
Insufficient fuel supply to the carb.

If this is still happening the engine running lean will generate way too much heat for it to dissipate and that can cause it to be very difficult to restart but usually pulling the choke on full alleviates this situation.
Note it does not fix the problem , just works around it.

However I will wait for the spark test first.
The important thing is you only change 1 thing at a time or every one ends up really confused.

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@bertsmoubile1 - Sorry for the extremely long delay getting back to you with my testing results. I was able to do some testing this weekend and I do have spark once I turn the motor off. I have noticed over the past two times mowing, that the choke issue I was experiencing before has gone away and now I can run the motor at full speed without having the choke pulled out a little bit.

Waiting for your next suggestion.

Thank you

Craftsman46

bertsmobile1 said:

And to pick your memory, does the mower exhibit any other problems when running?
If you do not turn it off, does it stop all by itself ?

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@ BertsMobile1 I have one more update. I have noticed over the past two weekends if I attempt to start the mower after it has been running, the motor will backfire but never turn over. In my research I thought I read once that this could be a sign of a flooded or malfunctioning needle in the carb.

I hope this extra information helps.