My generator has had a problem starting. It will turn about 1/4 to 1/2 rotation and then lock up. The controller disengages the starter and the unit shows a crank failure. If I wait a minute or two and then try, it'll start immediately.
At first I thought it was some form of vapor lock. But, after checking out everything recommended in the repair manual ive come to the conclusion that it's probably the compression release mechanism on the camshaft. 
My question is... Is there any way I absolutely determine that it's compression release without tearing the engine apart?
What I've done already: new battery, rebuilt the starter, check NG regulator pressure, checked and lubricated choke, 
I'd attach a video of the starting but the file is not a type thats accepted as an attachment.
 
Many thanks in advance for any assistance...

Remove the valve cover.
 
When the cam raises the exhaust valve, besides seeing the normal opening of the EXHAUST VALVE, there should also be a very slight "bump" (opening) of the valve.  This is what causes the decompression when cranking.  I believe the exhaust valve on your engine is closest to the sump.
 
So, if the exhaust valve opens and closes smoothly, no slight bump, the CR is broke...  
 
Another tip is to turn the engine to the compression stroke, TDC. With the engine in that position, it'll spin fast initially (CR not needed).   
 
 
 
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