Trouble getting gas into tank while on water

1999 Rinker 232 BR. 5.7 Mercruiser. Aplha One.

Problem: Cannot pump gas into tank when the boat is in the water.

Last year filled boat on land, except once at end of season when runnig low and tried to add gas at marina pump with less than 1/4 tank showing on gauge (while boat is in water). Gas pump would click off due to the gas rising up to the top of the gas tank neck, about two to three inches from the gas cap.

I forgot to follow up with mechanic during winterization and filled it on land before first launch this year.

There is not a release/air valve or tube on outside of boat near gas cap (over the phone my mechanic told me to check valve, possibly blocked from insect, etc...there isn't one)

My theory is that the boat is level and not moving on trailer therefore I am getting gas in. But should be able to fill boat on water as well...

I wouldn't mind the problem if it would stop using gas while I run it

Any thoughts or suggestions??

Thanks.

B

Re: Trouble getting gas into tank while on water

Hopefully someone will chime in, but I never heard of anyone having problems gassing up at the marina. Even on our lake, the water gets rough at the marina, because the launch ramp is right there, and it is a convergence of the lake and river coming together, as well as pleasure boats going by at decent clips. Very odd.

Re: Trouble getting gas into tank while on water

Either the vent is not venting properly or you are trying to fill too fast so that the vent cannot keep up.

The vent is required to allow air to escape from the tank as the tank is filled with gas. If it cannot vent it is pretty easy to get an air pocket trapped and it will not allow more gas to go into the tank.

Re: Trouble getting gas into tank while on water

did you have all the passengers sitting in the back of the boat, move them forward, i had one that was hard to fill, putting weight in the bow helped. you probably have a fill/vent combination, you have to have a vent of the motor would not run.