Full Tank of Gas

I have a 2016 Moomba Mondo. We don't have a gas station on our lake. With the boat on my Boatmate trailer I don't get a full tank at the gas station. In order to get an almost full tank I park the boat on the trailer on a downward incline and I get 6 to 8 more gallons by manually pouring in gas cans, and the gas gauge is still slightly below full. Is there a better way?

Thanks much.

It takes as much time for me to get the last 4-5 gallons in as it does the first 20 when filling up.

Have to climb up in the boat so I can watch the fuel gauge to confirm it’s full.


Very strange.

I always wondered why the fuel gauge never reads 100% full after I fill up. I assumed that the gauge was off. Would be nice to get another 8 gallons in...

I have found that setting the gas pump to the slowest automatic setting gets me most of the way there and towards the end I have learned to "hear" the gas going in and take my time. usually gets to 100% this way. I'm with tex in that it takes a minute to do it.

I don't ever run the pump at full bore and have learned from an overflow all over the parking lot in my old supra to take it slow.

Good tip San. Never thought about running the fill pump slower to help insure a complete fill.

Will try that on next refill!

Interesting. My Supra SE does the same thing. I'll have to try that.

not sure how moomba/supras fill but on my current whip, and for that matter the prior 2, if I turn the pump on full steam it shuts off often and doesn't like running once it's about 90% full.
found that on the slowest setting it fills steady.

Not sure this helps, but I manage to get a full tank (2018 Mondo) of gas by running the pump slower after the initial stop just like sandm points out. While it works to put more gas in, it will still stop again as it gets fuller. When this happens, I wait a few seconds to restart the pump. While waiting I will actually rock the boat on the trailer to slosh the gas around a little to release any air trapped in the neck of the boat fuel line. Mind you all theory at this point, but I always manage to get a full tank of gas ��

Never thought about the rocking action.

Not sure I’m strong enough to rock a 4200 lb. boat. LOL.

Does not take much to shake it around a little. I lean on it with my shoulder and give it a couple shakes/pushes. Probably looks a little odd to other folks getting gas that are gawking at the boat as I fill up, but it is not to obvious what I'm doing.