The trouble shooting starts with a compression test.----Post the actual values here.----Next is a spark check.----Do you have spark that jumps gap of at least 3/8" on all leads?----The surging points to a fuel supply issue.
It should slide right off.-----In salty water the prop should be removed about once a year to grease the splines.-----Try a hammer and a block of wood.
Simple job to replace the o-ring in there.-----But I have seen this presenter trying to hammer tapered dowel out of V-4 and a V-6 block.----Trying to POUND them out in the wrong direction.
Just 22 bolts to remove cylinder head.----No timing issues involved.-----Easy on a fresh water motor.----A simple test device is used to check peak output of the electronic magneto.----Buy one for say $10 or make one with wire , cardboard and glue.
Checked thermostat ?----Does spark jump a gap of at least 3/8" on the 3 leads ?---The motor is 45 years old and possibly 5 owners.-----Remove head gasket to inspect cylinders.----Head gasket is cheap compared to ignition parts / carburetor kits or an hr labor at a big shop !
Any pictures of this motor and the 3 coils ?----Perhaps some inventive person was trying to modernize this motor ???-----Or a newer motor with an older identification plate???
Use a sharp pointy tool.----Remove o-ring.-----Install the new o-ring.-----That hole may spray water into the exhaust for cooling.----Do not fuss over that hole.
