55 hp Yamaha timing issue

[spooky90]

My 55 hp Yamaha started to run poorly and seems to be out of time. With #1 piston at TDC, the timing pointer is about 20 degrees after TDC indicator. Motor starts but seems not to have power on #1. Carburetors are OK. Magneto key is in place and not broken, Timing is about 20 degrees retarded on both #1 and #2 marks. Flywheel appears not to have slipped on shaft. Does anyone have a clue. Motor will sort of clear out with full throttle and seems begin to run on both cylinders after a few hundred yards, but has little power and about 2/3 of regular speed. Compression is fine.

[boats.net]

Check to see if timer base is sticking and not returning back to idle position.

[spooky90]

The timing pointer is too far off to set. I don't think the issue can be with the base.