Gas Cap vent and propeller grease

[brooksville_rebel]

Hello

Since my fuel gauge doesn't work I wanted a quick way to read the fuel. So found this cap online.
Kelch 54-1815 13.5" Gauge Gas Cap
Amazon.com: Kelch 54-1815 13.5" Gauge Gas Cap: Automotive

Fits just fine and reads pretty close. And thats all I wanted for now. Well what I didn't notice or taken in was that the cap currently on my gas tank (and this is not one of them red plastic cans) has a small screw on the top of it. Quiet honestly I normally forget about it anyways. This new one has no vent on it. My tank is a pretty big one. A 24ft pontoon
Is it gonna matter that its not vented ? If so can I just loosen it up when out boating ?

Thanks
Mark

 

[oldjeep]

Re: Gas Cap vent and propeller grease

You need a vented cap if you want the fuel tank to stay in its proper shape and the boat to stay running Loosening it is not a very good idea.

Its not that hard to change the level sender on a pontoon tank - why not just fix it correctly?

 

[brooksville_rebel]

Re: Gas Cap vent and propeller grease

And why wont it stay in its proper shape ?
I plan on it but right now time is not available.

 

[oldjeep]

Re: Gas Cap vent and propeller grease

And why wont it stay in its proper shape ?
I plan on it but right now time is not available.

Because as you suck fuel out of a tank, air needs to get in to fill the space. If you suck fuel out with no vent it collapses the tank until the motor can't pull fuel hard enough against the vacuum and stops running.

 

[gm280]

Re: Gas Cap vent and propeller grease

If you don't use the proper vented tank cap, you will absolutely run your engine out of fuel and maybe not know why the engine shut down either. Others have gone down that road before learning.

 

[brooksville_rebel]

Re: Gas Cap vent and propeller grease

Thanks. I went and read up on it. Not sure why I didn't think of that and the unequal pressure and all.
My science teacher wouldn't be happy.

 

[Home Cookin']

Re: Gas Cap vent and propeller grease

nothing wrong with leaving it a little loose while opertating; that' show it's done with lots of tanks.

 

[MH Hawker]

Re: Gas Cap vent and propeller grease

And I use this for prop grease, 2-4-C With Teflon (92-825407A12)

 

[oldjeep]

Re: Gas Cap vent and propeller grease

nothing wrong with leaving it a little loose while opertating; that' show it's done with lots of tanks.

On a pontoon tank where it is less than a turn to remove it and the tank sits on the motor pod - you better bring a spare because it'll go for a swim.

 

[Home Cookin']

Re: Gas Cap vent and propeller grease

I have never had a loose cap bounce off in 55 years of boating, including on rough water and jumping tug boat waves. And many are rigged with a chain or other attachment so they can't fall off.

 

[Chris1956]

Re: Gas Cap vent and propeller grease

That gas cap has a long float device on it. It would need to jump straight up about 24" to get free from the tank. That is not going to happen, due to any bump or wave, you can survive.

 

[bruceb58]

Re: Gas Cap vent and propeller grease

The cap you got may actually be vented although some people on Amazon say it isn't.

All of these are vented.
BluSkies E-Commerce Web Site - Fuel Level Gauges

Go to kelch.com and ask them if your particular cap that you purchased is vented.