Gas tank pressure problem

[highcking]

I am the new owner of a 1959 Johnson ten horse, and also new to this forum. I tested the motor for the first time today. It would run after being primed from the tank (this is the two-hose style motor and tank) but no air pressure would develop in the tank so it would soon stall. I checked the air hose connection at the motor's manifold, it is in good shape. The gas tank holds pressure because I let it sit in the sun awhile and it hissed loudly when I cracked the filler cap open. I could also get a hiss if I opened the tank's connector to the motor using a small screwdriver. But no hissing from the tank after running the motor a minute or two. What is the most likely problem here? Clogged air fitting on the motor? Bad connection between the motor fitting and the tank fitting? Thanks in advance.<br /><br />Bill Shields<br />Vienna, Virginia

 

[Joe Reeves]

Re: Gas tank pressure problem

If the tank holds pressure, and the engine is pumping air down the line to the tank, either you have a leaking "O" Ring in the fuel connector (which you seemed to have already covered), or the tank is only half full, 1/4 full something of that nature.<br /><br />If the tank is not full, it takes considerable time for the engine to build up the proper tank pressure. The work around in which case is to simply pump the primer button on the tank occasionally until the pressure exists.

 

[highcking]

Re: Gas tank pressure problem

Thanks, Joe. I only had a small amount of gas in the tank. I'll see what happens if I fill it full.<br /><br /><br />

Originally posted by Joe Reeves:<br /> If the tank holds pressure, and the engine is pumping air down the line to the tank, either you have a leaking "O" Ring in the fuel connector (which you seemed to have already covered), or the tank is only half full, 1/4 full something of that nature.<br /><br />If the tank is not full, it takes considerable time for the engine to build up the proper tank pressure. The work around in which case is to simply pump the primer button on the tank occasionally until the pressure exists.

 

[Chinewalker]

Re: Gas tank pressure problem

I had a '59 18hp with a similar issue. Turned out the air connector at the motor was plugged. Bug, mud, something... <br /><br />Easy test - prime up the motor, start it, then disconnect the fuel connector. You should get air blurbling out of the air nub on the male connector on the motor as the motor runs. You should feel and hear air coming out of it...<br /><br />- Scott