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I have a 1982 Lawn Boy 7229 F100 series that I can’t get started. It does not appear to be carb/fuel related or electrical. What I have done so far; cleaned carb, checked for spark, checked flywheel key, cleaned magnets on flywheel and ignition, cleaned and checked exhaust ports, tried spraying starter fluid into carb throat and also directly into spark plug hole. i don’t have a compression checker however it appears to have some compression. I have an identical machine to compare it to which runs great and they feel about the same compression wise. This machine ran great up until now. It doesn’t even start to ignite or sputter when trying to start it. The only other observation I made was when cleaning the exhaust ports and watching the piston move up and down, a little fuel seems to squish out into the exhaust ports, not sure if this abnormal or not.
Is there anything I may have mised that I need to check? Any suggestions are greatly appreciated. Thanks.

Has a good healthy spark ? , if so try another plug just to be sure .

Strange it is not firing at all .The only other thing could be a crank seal that is really leaking badly .

Yes it is strange, it has me stumped. I did try another plug, forgot to mention that. Thank you for the response though.

If you put fresh fuel mix directly through spark plug hole and got nothing then it almost has to be either low compression, or faulty spark/no spark. Put a teaspoon of oil in the plug hole and try again. If you rule out low compression as the culprit then I’d temp install a known good CD module to confirm a faulty module, or intermittent plug wire.

I'd check or replace the lower crank seal , if it's sucking air it may not be getting the fuel charge into the cylinder , there has to be enough vacuum created to pull open the reed valves and move the fuel charge to the ports .
I see you used starter fluid in the plug hole , I'd use the gas mix instead of starter fluid .
You should be getting a bit of fire with that I would think unless the compression is really low .

And as lawnboy77 mentions it could be a bad module too:tongue:

You mentioned checking for spark, but not the quality of the spark. This is critical. Maybe you know this already, it should be a "fat" blue or bluish-white spark, that snaps in the open air. A weak thready spark, yellow/orange etc., is no good and when under actual compression in the cylinder the spark plug won't have enough energy to jump the gap. Hope this doesn't sound like a lecture, but it's important to define our terms.

It not going to cost anything,try to put some heavy oil in spark plug hole and give a pull.

Thanks everyone for the replies and advice.
Spark looks healthy. You hear the snap/crack across the gap. The color of the spark is whitish.
I will try the oil in the cylinder and also check the crankshaft seals.

So I tried pouring a teaspoon of oil down the spark plug hole. 2nd pull it started. It burned off the oil and I let it run awhile. Shut it down and restarted it on the 1st pull. Did this several times in succession. Then let it cool down for an hour and it still started on the 1st pull. So now I will wait a few days and see what it happens.

Update. Attempted to cut the lawn. Started right up. Ran but you could tell it wasn’t firing smoothly. It almost seemed like it was misfiring slightly. As time went on it seemed to be losing power as well. It actually stalled a couple of times in the course of an hour. It did restart each time though.

I have an identical mower so I have a good baseline to compare it to. I tried a simple compression test, rotate the blade in the opposite direction the blade usually turns until you feel compression than give it a push in the normal direction. It should kick back. Of course do this without the spark plug connected. I now can see a big difference in compression between the 2 machines. The troubled machine has much less compression.

I don’t see any signs of wetness near the upper or lower crankshaft seals but do see some fuel that I think is leaking from the ports. I suspect the machine needs a ring job

I read where you checked the exhaust ports, but not seeing anything about checking/cleaning the muffler. From my experience with the F series engines the mufflers are quicker to sludge up than the ports. I clean my F series mufflers on the BBQ grill. Set it to high for about 45 mins and it will burn all that sludge to ash, then just hose it out with the garden hose. A word of caution though, don’t use this method on mufflers that are cast aluminum, use it only on the stainless steel ones. The cast aluminum mufflers tend to distort when cleaned in this manner. A poorly breathing 2 stroke will display some of the symptoms you are describing. Lack of power, stalling and hard starting. Your cylinder compression might be on the low side as well, but a poorly breathing 2 stroke will compound the compression issue. Minimum cylinder compression is 80 psi for the F series. I think a small engine shop could check it for you for a small fee.