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Old 07-10-2002, 08:36   #3
Senior Member
Join Date: Nov 2001
Posts: 3,111

Re: Mercury Boat Motor Problems---Please Help

Originally posted by Marty Hayes
Sometimes I can get it to stay in plane by pumping the gas line bulb.
When you squeeze the primer bulb, you are acting as a manual fuel pump, which means you need a.... fuel pump?

If you feel like rebuilding it, you can usually pick up a diaphragm kit for much less than a new fuel pump.

Usually, a fuel pump problem won't be noticeable until you get up to speed, because even a diaphragm with a pinhole in it can feed enough fuel to run at lower speeds.

Generally speaking, assuming no line-kinks, restrictions, etc...

If squeezing the bulb affects the problem, it's a fuel pump problem.

If it doesn't affect it, but hitting the choke (or spraying fuel in the carb) does, then it's probably a clogged carb.

If your fuel pump is fine, but squeezing the bulb helps, that would be an extreme restriction between the bulb and fuel pump (filter, kink, etc.). If the restriction was before the bulb, it would suck the bulb shut. (Usually not the case... more likely a fuel pump problem.)

Outside of that, you can easily eliminate external fuel system problems by hooking a known-to-be-good remote tank & line directly to your fuel pump fitting. If the problem is still there, you elimated the lines, tank, external filters/water separators, anti-siphon valve, etc.

Hope that helps.
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