Chainsaw Repair

No--it's not a chainsaw but engine is close?
I recently bought a Stihl HS86T Hedge Trimmer. It was understood that it had a running issue, mainly wouldn't idle. After a thorough cleaning, I found the muffler spark arrestor completely plugged
The trimmer runs perfect and idles fine but the problem is with pull start
This was bought for my wife and she has no trouble cranking her Echo string trimmer, leaf blower or even my chainsaws.
However this trimmer has so much compression, she has trouble with going through ONE compression stroke
I am not new to two stroke engines and have rebuilt hundreds.
Now, since the screen was so blocked, I am suspecting a high amount of carbon build up in the combustion chamber. Just hate to teardown a perfectly running engine.
Have any of you ran into this before?

Well, she's definitely mean but not very strong or determined 
Another strange thing is that I can't find a single on-line parts diagram for this hedger, even from stihl
This is a commercial product that is About three years old and I have only found the operators manual
I just feel that there would have to be an enormous amount of carbon to cause this problem.
I will have to find a way to use my compression tester because it has the tiny sparkplug.
That will be simpler then tearing into
the engine.