2001 Mercury 25 sel 2 stroke. Bogging down.

[frobotz]

I took the boat out last weekend. Ran fine. Shut it down and started up several times to fish. No issues. Went to head back to the ramp and it was bogging down. Got back home. replaced plugs (needed it anyway) cleaned the fuel filter and ran fuel thru the open lines to the filter just to check for clogging. Found some sediment in the system. Reinstalled the fuel filter. fresh tank of 50:1 fuel. Ran it yesterday and its still doing the same thing. I pulled one plug wire at a time at the launch and it wouldn't start on either plug . Runs smooth at the low end. but feels like it hits a wall at full throttle. I am thinking its time to clean the carb, but thought I would post up here for ideas. What are your thoughts. its a 2 cylinder 2 stroke motor. low hours. Don't have a compression tester but feel like that's probably not it since it just happened out of the blue. '

What ideas do the experts have? What are your suggestions.

Thanks in advance.

 

[frobotz]

Cleaned the carb. It was extremely clean inside. Nothing to note.

 

[frobotz]

How often (plausible) would it be to have sheared the crank index pin? Don't have time to get to it yet. But I think that's where my next step will be. Pull the flywheel off and have a look. Guess just a puller needed for that right?

 

[frobotz]

The key on the flywheel is still intact. Running out of ideas. Anyone? motor idles good, runs ok till it get to the top end them just flattens out at 3.4 throttle and wont accelerate. Please help.

2001 mercury 25el.

 

[frobotz]

Compression checks good. Both cylinders over 120.

I am open to any ideas or suggestions. .

 

[frobotz]

So I am thinking this may be an issue with ignition advance.. Runs great at the low end. but wont increaser RPM over about 3/4 throttle. How is the ignition advanced? does the trigger switch or just rotate over like the older motor did. I cant believe no one here has any ideas at all.

Leave it to me to have a problem that stumps everyone. Just my luck.