Intek 6HP engine jerks back ripping cord out of your hand during starting.

A friend just gave me this DR trimmer that has a 2001 or 2002 Intek engine model 121607-0218-E1 because of it jerking the starter line back. Usually this would be the woodruff key sheared off in the flywheel changing the timing but it looks as good as the day it was installed, I removed the oil pan/bottom plate to check the gears to see if maybe a tooth was missing or it had jumped a tooth but everything looked correct and now not sure where to go from here.
 
The trimmer is in great shape and would like to get it going again with this engine but if I have to I would replace it but haven't been able to find a replacement engine for it yet, any suggestions on how to repair this engine or a replacement for it ?

Did you check valve clearance before tearing it apart? Adjust them as necessary then rotate the flywheel by hand. You should see the exhaust valve move momentarily which releases some pressure on the compression stroke. If it doesn't the acr has failed. The direct replacement engine is a 121S07-2060, short block 692745. The engine may be cheaper.

I have to admit until you mentioned the ACR I didn't know it had one, found a quick video on youtube that explained it and will check it first thing tomorrow, I'm assuming that if it doesn't work the camshaft will have to be replaced.
 
I did forget to check valve clearance before I pulled the sump so will slip it back on and check.

You have found your problem. When looking up parts leave the -E1 off.

That what I come up with, my date code is 98062656 and can't find the standard cam, any chance the cam with the worm drive extension is the same cam just by removing the worm drive ?