WOT engine starts to rev down

WinnipegBoatMan

Petty Officer 3rd Class
Joined
Nov 5, 2009
Messages
91
Hey all,
I have a 1994 30Hp merc, 2 stroke that i just baught a week ago. It was a great deal, it came with a 16' aluminum starcraft boat, livewell, and trolling motor.
I finally got it out on the water yesterday, and it fired up with one pull (manual pull Start) and idled perfect, warmed it up, and it shifted perfected!
Next got it on plane, and about 5 minutes later gave it WOT. I got the boat up to 39MPH no problem!
Ran it for a bit, then came back ot the dock, and picked up my dad, and uncle for a ride. Got it off the dock and got it on plane, and then WOT. The WOT lasted for about 5 minutes, then the engine began to rev down slowly to an idle. I turned the motor off, then gave it choke, and then it fired up again no problem. Got it back to WOT, then again it began to rev down.
The first thing that came to mind is the vent on the gas was plugged.. but I had the whole cap off, and it would continue to do it again!
The only thing that worked, was to push the primer bulb on the motor to give it extra fuel in the carbs.
I even added Sea Foam into hte fuel to clean the crabs, and it seemed to help, only to an extent.

Anybody have any ideas? The fuel filter is clean, i have fresh gas? Could the carbs be gummed up?
Thanks
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: WOT engine starts to rev down

It could be junk in the carb but from experience I would rebuild the fuel pump first and be sure to replace the check valves with the new style that comes with the kit from Merc.
 

sxmerc

Petty Officer 1st Class
Joined
Jul 13, 2010
Messages
247
Re: WOT engine starts to rev down

Fuel pump... yes. Overhaul the carbs while you're under the cowl.
 

WinnipegBoatMan

Petty Officer 3rd Class
Joined
Nov 5, 2009
Messages
91
Re: WOT engine starts to rev down

Thank You Gentlemen for your Replys!
I'll get on the work ASAP!
 
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