Lawn Boy Model 7229 F100 Series Won’t Sart

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.