Yamaha 150hp primer bulb not getting hard?

[ErikE]

Buddy of mine had synthoms of a bad fuel pump ,he had to pump the bulb. Had a mechanic replace the fuel pump and the lines. It worked for 3 days and then it wouldn't pass idle or get on plane. I notice when pumping the primer bulb it wouldn't get hard also while pumping you can here the fuel flowing in the carbs but you cant see it.

Anyone know whats happening here?

[jtb]

try pulling the fuel pump off and pumping the ball to check for leaks, it takes a 10m socket. also try trimming up the engine with the ari box off while pumping the ball and see if the fuel is comming out of the carbs-
Hope it helps,

JT

[ErikE]

Isn't there 2 fuel pumps? Small rectangular black boxes? thanks

[VectorPat]

What model engine is it?

[Jason Johnson]

Check fittings at tank

[HP]

Sounds like it might be an anti-siphon valve on the fuel tank:rolleyes: They have been known to stick. The bulb will seem to get firm but it won't stay after you are underway. If I were you I'd remove it. They have been known to lean an engine out:eek: .......hope this helps

[jtb]

stuck anti ssiphon will suck the ball flat

[ErikE]

I am pumping right out of a portable tank bypassing internal fuel tank and fuel/water separator. I haven't tried again since my first post.

I was wondering if I take the fuel pump off and unplug the output side and pump the bulb should fuel come out or no? I'm not sure if this is what "jtb" was trying to say.

I'm not sure what model it is but it looks early 90's 2 stroke, carbs and I think fuel pump runs with pressure/vacuum not electric.

Thanks

[VectorPat]

yes fuel should come out.. before you unplug the outlet with the pump off of the block, pump the bulb and see if fuel comes out of the hole on the back side of the pump. if so the pump is bad.

[jtb]

I am pumping right out of a portable tank bypassing internal fuel tank and fuel/water separator. I haven't tried again since my first post.

I was wondering if I take the fuel pump off and unplug the output side and pump the bulb should fuel come out or no? I'm not sure if this is what "jtb" was trying to say.

I'm not sure what model it is but it looks early 90's 2 stroke, carbs and I think fuel pump runs with pressure/vacuum not electric.

Thanks

this is what i was tring to say, idrink alot and things dont always come out clearly.....thank you J&B
if you plug the out put side it should hold pressure.
if the rubber is bad in the pump it will leak from the press/vac hole that mounts to the intake.

[ErikE]

Thanks guys, I'm gonna try it this weekend and ill let you all know.