My Mechanic Doesn't Know Whats Wrong

[bamamako]

2006 MERCURY 4-STROKE 90hp

THE PROBLEM I HAVE IS MY MOTOR WILL GO DEAD USUALLY WHILE RUNNING WOT. I HAVE REPLACED THE PRIMER BULB . THE MECHANIC REPLACED THE FUEL PUMP . SAME PROBLEM. WHEN THE MOTOR GOES DEAD IF I PUMP THE BULB IT STARTS RIGHT UP. NORMALLY I NEVER PUMP THE BULB, NOT EVEN WHEN I START IT . NEVER NEEDED TO. THE BULB FEELS LIKE IT IS FULL OF AIR, EVEN THOUGH I HAVE TRIED TO GET IT ALL OUT. HELP PLEASE . THANKS.

 

[CharlieB]

Re: My Mechanic Doesn't Know Whats Wrong

Temporarily install a clear hose between the fuel pump and carb, watch for any air bubbles indicating air leaking into the fuel line.

You may have a leak at a fitting that allows air to be sucked in, the fuel pump is then unable to pump enough fuel for WOT running, you simply run out of fuel.

Continued operation with this problem WILL cause lean running, radically increasing piston temps to melt down.

 

[bamamako]

Re: My Mechanic Doesn't Know Whats Wrong

Thanks , I'll try that and let you know how it goes.

 

[j_martin]

Re: My Mechanic Doesn't Know Whats Wrong

First part to replace = mechanic.