: Fuel Bulb Pressure


Metsman
08-15-2008, 05:21 AM
When I run WOT for a length of time with my 60hp 4-stroke Merc EFI, after a time it will cut out due to lack of fuel and I need to "pump" the bulb.
I disconnect the bulb and it pumps up real hard.
I reconnect it and it pumps fairly hard but goes "soft" at WOT cutting out ...where is my fuel pressure problem.
At lower speeds there is no fuel pressure problem.
Thanks.

Metsman

Hot Runr Guy
08-15-2008, 06:13 AM
I don't have my Merc 60 4S anymore, but I believe that there is a fuel filter before the fuel pump, under the cowl. I'd check the filter first, then move on to the fuel pump itself.
HRG

taithelles
04-18-2011, 06:15 AM
Went to the dry bulb and will not pick up any gas I had to remove the gas line from the motor side of the bulb and it picked up the gas on the spot and put together again, and not the many health problems since then. I bought a new bulb and have it just in case. Not sure what is happening.

Jerryv
04-18-2011, 01:09 PM
Check all the clamps and fittings on your fuel line. Also the quick connect if you have one. It is probably sucking in air somewhere between the tank and the engine. If there was a restriction in the tank and no air leak it would suck the bulb flat.

Jerry

staylor
04-19-2011, 06:33 AM
...on a 25 merc. You'd run for awhile, lose power and the bulb was not sucked flat- but was not firm and needed 5-6 pumps to firm up. I'd disconnect the quick disconnect at the motor and let some gas squirt out and then it would run fine for a while with a firm bulb. Turned out that I was leaving the excess fuel hose loose at a level below the tank and a vacuum was forming in the lines. All my tank fittings were good. I finally just wrapped the excess hose around the top of the tank and made sure the bulb was higher than the tank pick up...and the problem went away. Another possibility is a clogged tank vent. Try running with the fuel tank cap loose for awhile and see if the problem stops. I once fixed a little Suzuki motor that the owner had run for 4 years with this problem. The tank was on the motor- I think it was a 2 hp, and whenever the motor would stall he'd just let it sit for a minute and then restart. It turned out that the vent hole in the fuel fill cap was not drilled with a large enough vent hole- it was a really tiny hole around .02 inch diameter. I drilled this out to .052 and the motor never stalled again.
Doug