No top end 1984 Merc 60 hp 3cly Direct charge POS

[mk30h]

Merc 60 hp 3 cly 1984. This engine is driving me nuts. Until last week, the engine was running well, then had to change tanks and she wouldn’t start- battery dead. Paddled to shore and then walked home, towed the boat home next day and charged the battery.
Now the engine seems to be going about ¾ when wide open. Just does not open up. Replaced the fuel pump diaphragm- no change. Next will try the carbs.
Any ideas what could be causing this problem? I haven’t checked compression yet, but will try. This engine has less than 50 hrs on it since new and has never run right. Was already rebuilt once- (burned upper piston) when water pump failed.
The boat is at a remote location, and short of pulling it out for the summer, any suggestions besides using it as an anchor would be appreciated.

Thanks guys

[scud]

Compression test is what most mechanics do first with a two stroke outboard. All cyl must be within 10% of each other
Step two test spark with spark plugs installed spark should jump 1/2 inch.

Third replace fuel

[j_martin]

If it occurred when you changed the fuel tank,
1. Replace the fuel filter.
2. Clean out the entire fuel system, except carbs after the filter.
3. Clean out or replace the tank.

You got some chit in the fuel system when you changed the tank. If you continue to run it while it's starving, you will soon get an education in major engine overhaul.

hope it helps
John

[j_martin]

On second thought, you probably got a gob of water in the carbs and they will need cleaning also.

hope it helps
John

[mk30h]

Thanks guys.
After checking the filter, the jets and cleaning the carb, discovered the real culprit. The timming advance linkage had broken under the stator, piece of plastic just snapped, and unless you played with throttle you could not see the break. Now to pull the flywhell and see if Merc has the replacement part or I visit a boneyard. Local merc dealerd didn't even have jets instock.