Primer Bulb Goes Flat On Merc 150

[cwarren902]

I have a 99' model 150 v-6 Merc. My primer bulb sucks flat after about 15 seconds of running at idle. I have checked the vent hose and there are no obstructions. I checked the fuel line from the tank to the bulb and there are no obstructions there either. I replaced the primer bulb thinking that was it and it does it just as bad. I blew air through the fuel line back into the tank (with an air compressor) thinking that it might have a screen on the pick-up line inside the tank and maybe it was dirty. There seemed to be a check valve in the line because the air would not go into the tank. This also seemed to make the problem worse. Im not familiar with what is inside the tank so any suggestions would be appreciated. My boat is a 99' nitro 185 sport fish and ski.

 

[hkeiner]

Re: Primer Bulb Goes Flat On Merc 150

One way to troubleshoot this type of problem is to use a vacuum gauge. If you decide to do this, the below Service Advisory may be helpful.

 

[ReelDuel]

Re: Primer Bulb Goes Flat On Merc 150

try blowing air from the fill to the bulb. What type of fuel filter system do you have?

 

[cwarren902]

Re: Primer Bulb Goes Flat On Merc 150

Its stock I guess.

 

[ReelDuel]

Re: Primer Bulb Goes Flat On Merc 150

do you have an external filter behind the bulb?

 

[cwarren902]

Re: Primer Bulb Goes Flat On Merc 150

the only filter I can see is the little white one above the fuel pump on the motor.

 

[parkpoint831]

Re: Primer Bulb Goes Flat On Merc 150

The Tank Itself Has A Filter In It And Mat Be Plugged. That Would Make It Flaten Out.

 

[DRIFTER_016]

Re: Primer Bulb Goes Flat On Merc 150

You didn't say wether the tank is built in or portable.
If it's built in it sounds like there may be an issue with your anti siphon valve.
It is usually located inside the fitting that screws into the top of the fuel tank.

On my tank the anti siphon valve is just a brass fitting that the fuel line connects to. You can remove the fitting and soak it in carb cleaner, that may fix the problem. If not just install a new one.

 

[cwarren902]

Re: Primer Bulb Goes Flat On Merc 150

Hey thanks for all the help guys, I found the problem and it was the anti-syphon valve.