31cc MTD 2-cycle compression test numbers?

bond-007

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Using a standard automotive tester, I'm seeing 60psi max after a couple of pulls. My Toro string trimmer shows 90psi. Not sure what to make of the result, since I don't have the repair manual/specs for the engine.
If the compression is wrong, what could have gone wrong? It seems unlikely the cylinder is scored, more likely something I did has caused the valve to not operate as intended and provide adequate compression.
With the sparkplug replaced and the EZ fire lever (choke?) engaged, I eventually get combustion smoke from the muffler after a few pulls and it occasionally sounds like it will almost fire but not quite.

It ran fine (years ago) but the pull-start mechanism failed. I replaced it (incorrectly) and found a sheared flywheel key (integral).
I got a new flywheel (with an integral key) and it is all back together, and I am trying to get it to start.
Supposedly the flywheel is the correct part but I suppose it could be wrong in terms of too many variables changing to isolate the issue (I do get spark on the spark tester and can see it).
 

StarTech

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First a standard automobile can't be use with such small CC engines; unless, it is designed to do so. I use an Actron version that is. For most 2 cycles you will need a bare minimum compression of 100 psi.
 
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