2001 Mercury 25el. Dont think the timing is advancing under throttle. Any ideas.

[frobotz]

Motor ran great. Shut it down when I restarted it. would not go over about 3/4 throttle. Checked cleaned fuel system. Compression test (120 + per cylinder) spark check. both cylinders firing, new Plugs, Cleaned the carb just for good emasures. Was clean as a whistle. so I think I have a timing advance issues. Been trying to research it. but I cant find anything about how the timing is advanced on this little motor. I did find a chafing spot in the wires for the stator but it doesn't appear to have gone into the wires. just the shielding.

Anyone have any video link or info that would help me understand timing advance and any timing checks on these motors.?

Thanks in advance.

 

[flyingscott]

On your motor the timing advance is not mechanical it is controlled by the switch box. If you look under the flywheel by the throttle assembly you will see the control rod for the stator is connected permanently to the block. Since it's not adjustable it is probably not your problem. What is your motor doing.

 

[frobotz]

When I throttle it up, its like it hits a wall about 3/4 throttle. Was running great before, Stopped to fish a little, started it back up and felt like the throttle was only opening 1/2 to 3/4 but the throttle is opening all the way. Boat gets right up to the point where it should accelerate and plane out but wont rev high enough to get there. , Ran great 20 minutes before.

Thanks for your help on this. Its has been a ghost town on every thread I have posted so far. Think I have everyone stumped.

 

[flyingscott]

What happens when you pump the primer ball while this is happening. Your carb should have been rebuilt not cleaned as it contains the fuel pump and the primer.

 

[frobotz]

Pumping the bulb does not change anything tried many times. As for rebuilding the carb I would agree but it was clean to start with, I took it off to inspect and rebuild if needed. but the bowl and the carb was clean as new so I verified fuel flow thru the jests and air thru any passages and reassembled.