primer bulb won't hold pressure stays flat

kennykdm

Recruit
Joined
Sep 10, 2002
Messages
5
I have a 93 mariner 150 2.5 that I have ran only once. It ran great after getting it start. It took a little while to get it to crank but ran great after that. Now before I have tried to start it I would pump the bulb but it wont get any pressure, after 2 pumps the bulb stays flat and I cannot pump it anymore. I have changed out the fuel line and bulb, also changed out the fuel filter. The battery has full charge spins the motor just fine. All the fuel line look great but can a pinhole cause this problem? I am new to this and just want to go fishing!!!!!!!! <br />How much does a tech normally run and does this this sound like a major problem.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: primer bulb won't hold pressure stays flat

Check your Tank vent to be sure it's clear. Or take the Gas cap off and try it.
 

kennykdm

Recruit
Joined
Sep 10, 2002
Messages
5
Re: primer bulb won't hold pressure stays flat

The boat has 2 tanks and both vents are clear. I have tried it with the fuel caps off and on and still the bulb stays flat after 2 pumps it will go back to normal size after about 30 to 45 min.
 

jessieb

Cadet
Joined
Sep 14, 2002
Messages
12
Re: primer bulb won't hold pressure stays flat

i think your tank vent is stoped up try to clean your vent. a good way to do this if you have a porable tank is just change the cap if you have a tank mouted in the boat use an air line to try to blow air in the tank see if you can hear it come out the vent.
 

fshng4

Cadet
Joined
Jul 31, 2002
Messages
22
Re: primer bulb won't hold pressure stays flat

You say you have 2 tanks in the boat. Are these tanks portable or are they fixed tanks? How are you able to switch from one tank to the other - maybe you have a leak at your couplers. Remove the fuel line from the motor side of your bulb - start pumping your bulb to see if you are getting a good flow of gas from the bulb. Does the bulb stay hard when you pump it up disconnected this way. If so your problem is from your bulb to the motor. If it still collapses start looking from the bulb to the tanks. Another thing did you install a A1 Marine Grade fuel or did you use automotive fuel line. Give us some more details here. Power boats with internal tanks and fuel lines running mopre that 7ft must have A1 type fuel lines. These lines are extra thick with more reinforcing material and will not collapse under vacumn. May be your line is collapsing. I am not a professional but just some thoughts as I have just recently changed out my own fuel lines and bulb.
 

kennykdm

Recruit
Joined
Sep 10, 2002
Messages
5
Re: primer bulb won't hold pressure stays flat

The 2 tanks are fixed. They are controlled by a electronic switch. There is also a lever beside the drivers seat that swithes from tank 1 and 2. All lines are marine grade. None of the lines collapse just the bulb. Thanks for the help.
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: primer bulb won't hold pressure stays flat

There is either a restriction in fuel line leading to prime bulb or the bulb itself is defective.Tank not venting is also restrictive.
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: primer bulb won't hold pressure stays flat

kmartin<br /><br />Things that can cause this are:<br /><br />*Restriction in inlet hose to primer bulb<br />> kinked hose<br />> plugged hose<br />> plugged tank outlet (in tank)<br />> bad anti-syphon valve in tank<br />> poor tank venting<br /><br />*Defective primer bulb<br />> soft bulb<br />> plugged inlet check valve within bulb assembly<br /><br />*Electric selector valve stuck midway<br /><br />I'd disconnect the hose at the electric valve and see if the bulb expands. If it does, the restriction is between the valve and tank....<br /><br /> :)
 

fshng4

Cadet
Joined
Jul 31, 2002
Messages
22
Re: primer bulb won't hold pressure stays flat

Two tank hoses go into some type of electronic switching valve and come out as one line to the bulb. You would have 3 hose clamps at this point - 2 coming in and one going out. Does your mechanical switching device utilize the same valve or a separate valve. I would check each one of the clamps at this or these valves for a leak or a leak around the valve itself. I have seen clamps cut into fuel lines and make small cracks or holes in them which is a problem. Basically start at the tanks and check each clamped joint for tightness and for damage. Run it all of the way to the bulb. Once again disconnect the bulb from the fuel line to the motor and see if you have good flow of fuel when you pump the bulb
 

taz33911

Seaman
Joined
Aug 19, 2002
Messages
68
Re: primer bulb won't hold pressure stays flat

I'd double check the vent blowing air in the fill.If it is fine I'd check that switch for the tanks. try bypassing the switch on each line,with a straight fitting. If the bulb is going flat you are not getting gas either the switch or clogged screen on the pickup in the tank , or maybe anti-syphon valve.Even if it had a air leak it would not collapse,hold your figer over the pickup end of the primer bulb you will get the same result as the problem you have now. Something is preventing the gas to flow from the tank.
 

taz33911

Seaman
Joined
Aug 19, 2002
Messages
68
Re: primer bulb won't hold pressure stays flat

I'd double check the vent blowing air in the fill.If it is fine I'd check that switch for the tanks. try bypassing the switch on each line,with a straight fitting. If the bulb is going flat you are not getting gas either the switch or clogged screen on the pickup in the tank , or maybe anti-syphon valve.Even if it had a air leak it would not collapse,hold your finger over the pickup end of the primer bulb you will get the same result as the problem you have now. Something is preventing the gas to flow from the tank. sorry about the spelling on finger
 
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