I have a 1979 Glasply with a 100 horse Johnson outboard. I bought the boat recently, and just did a restore on it. I am having a problem with the primer bulb getting sucked down flat after running full speed for 5 minutes or so. I have an in floor 20 gallon fuel tank. I have replaced the entire fuel line, to include new bulb, line itself, intake tube in the tank, new fittings on both ends, and a new fuel/water seperator. There is no problem with the vent on the tank. What could be causing this?
Have you tried running on a portable tank to check things out? If your tank is venting and you have a new dip tube in the tank, it almost sounds like you have a chunk of something large floating around in the tank and getting sucked up against the dip tube after a while. Then when you stop it falls off the end of the tube and you get a clear suction again.
Starfish is right on , on its in the tank ...
I have seen the plastic fuel pickup tubes (dip tube)
inside the fuel tanks cut too long on installation ...
Sometimes it takes months to years for them
to kink at the end on the bottom of the tank
All of a sudden your 3/8 fuel line becomes
a 3/16 fuel line ...
Pull your pickup tube out and check it ...
__________________
"Opportunity is missed by most people because it is dressed in overalls and looks like work." ~Thomas Edison ...
We talked briefly this afternoon at the park. I had my little boat there trying to tune the outboard motor. I believe I agreed with the others earlier that it had to be the tank vent. I just wish I could tune carbs.
We talked briefly this afternoon at the park. I had my little boat there trying to tune the outboard motor. I believe I agreed with the others earlier that it had to be the tank vent. I just wish I could tune carbs.
Seasick,
Good luck with the Mercury carbs. Mark will get you all fixed up though I am sure.
I have checked a re-checked the vent, it works fine. I don't think I have a dip tube length problem as I had the same problem with the factory set up. The replacement dip tube is the same length as the factory one was, and it is cut on a 45 degree angle on the bottom as well. I suppose I could have some blockage in the tank itself though. What a nightmare.
Good luck with the Mercury carbs. Mark will get you all fixed up though I am sure.
I have checked a re-checked the vent, it works fine. I don't think I have a dip tube length problem as I had the same problem with the factory set up. The replacement dip tube is the same length as the factory one was, and it is cut on a 45 degree angle on the bottom as well. I suppose I could have some blockage in the tank itself though. What a nightmare.
If I were you ... I would still check the dip tube ...
__________________
"Opportunity is missed by most people because it is dressed in overalls and looks like work." ~Thomas Edison ...
Had the same problem a few years back and tried everything I could think of,,,,,finally went to the local paint store, and purchased a card of two screens designed to be put on the pickup tube of an airless paint sprayer. slid one on the tip of the pickup tube and tied it tight with a chunk of stainess steel wire. Solved the problem and lasted for years. Whatever it is is small enough to move around, but big enough to block the tube.
Vacum problem
Starfish
Re: Vacum problem
Linear Mode
