'94 20 HP Tracker/Merc dies but takes back off again

[Boxcar Wllie]

I was running into an issue that the motor at full RPM would all of a sudden lose all power, then once the RPM gets low enough, takes back off again. I had a new carb kit put in and the motor runs fine at a low RPM, but after it warms up, it try's to die again.

I am thinking ignition but am not familiar with the ignition system on these (understand OMC).

Any ideas what it could be or recourse with the outboard marine mechanic?

[Surface Tension]

My first thought would be the bowl is running dry at the higher RPMs.

Causes for that are.

Improper float drop. (fuel level in carb too low).

Weak fuel pump.

Air leak in the fuel line fittings.

Plugged fuel filter.

Bad fuel line or primer bulb. Some of the aftermarket fuel line/bulb deteriorate from the inside and end up restricting the fuel flow too much.

Gas tank not vented or too much restriction. In that case the bulb could collapse but not allays.

[RebelSS]

I'll go for pinhole in diaphragm or loss of pressure in fuel line.

[delcecchi]

If it does it consistently enough for this to work, try pumping the bulb as it starts to happen and see if that changes what is going on.

Also try running with the cowling or cover off and watch that little sediment bowl or whatever it is called on the side of the motor. It should be full of gas at all times, I think. Anyway you can see if there is any correlation with the gas level in there and the motor rpm dropping.

These might help figure out if it is a fuel delivery problem.

[BoxMN]

My first thought would be the bowl is running dry at the higher RPMs.

Causes for that are.

Improper float drop. (fuel level in carb too low).

After I rebuilt my carb on a 25 hp OMC, I had the exact same symptoms and found that I put the float in upside down It was basically doing what ST mentioned, running out of gas at higher rpm. So be sure to check the level of the float.

Good luck!

[Ufatz]

I must jump in here like a little ol' grandma and warn each and all that running with the engine shroud off can lead to attacks of stupidity. Like putting your hands and fingers in the wrong place at the wrong time.

That is all. Just a reminder.