Fuel Hose Primer Bulb Collapses

[Mambeaux]

[The author]] just bought a [1999 Boston Whaler 17] Montauk with a Mercury 90-HP two-stoke-power-cycle outboard engine. The outboard engine idles okay, but [when the throttle is advanced to the point that ought to cause the boat to] run at planing speed, the [fuel hose primer bulb] collapses.

[The author solicits] ideas [about the cause of the fuel primer bulb collapse], please.

[Phil T]

You have a blocked fuel tank vent. Before starting the motor, open the vent [on the fuel tank]. Close the vent when you put the boat away at the end of the day.

[Mambeaux]

I hope you're right! [The boat that is being discussed in this thread] has one of the newer Moeller 22-gallon fuel tanks. [The fuel tank] has a black button in the middle of the [fuel filler] cap, but [the black button in the middle of the fuel filler cap] doesn't move.

When I get home I will look [more closely at the black button in the middle of the fuel filler cap on the new Moller 22-gallon fuel tank}.

[Phil T]

The new EPA compliant caps are a total pita. Swap out for a cap with a screw type vent.

[jimh]

To interpret the conditions or status of the fuel primer bulb as a diagnostic of problem in the fuel system, read the article:

A PRIMER ON PRIMERS
http://continuouswave.com/whaler/reference/primer.html

in the REFERENCE section of the website. The REFERENCE section of the website contains well-researched and well-written articles on common problems.

A collapsed fuel hose primer bulb generally is caused by an obstruction upstream of the primer bulb in the fuel system.