Tank ventilation.

[bigoldboy1]

Can you tell me if a boat removable fuel tank should have a ventilation hole so that as fuel is sucked out it does not cause a vacuum in the tank.<br />It appears there is a rivet or something in the tank top, should this be free to move so that air can enter. Thanks a lot . Martin

 

[NathanY]

Re: Tank ventilation.

The vent on removable tanks (depending what brand) is usually on the filler lid. Normally just a little screw.

 

[bigoldboy1]

Re: Tank ventilation.

Thanks Nathan. Does this mean that air does need to get into the fuel tank and do you think that the rivet or what ever in the fuel filler cap should be loose to be able to move as at the moment it is corroded in place?<br />Regards.

 

[NathanY]

Re: Tank ventilation.

Yes, air has to get into the tank to replace the fuel that is being taken out. What kind of tank is it? Metal or Plastic?

 

[bigoldboy1]

Re: Tank ventilation.

Hi Nathan. I have two tanks with this boat and they are both the metal type with a proper plug connection and glass fuel guage, both hold about 25 litres of premix. By the way should the premix be 50 to 1 on this Johnson 75 seahorse? it is a 1981 engine.

 

[NathanY]

Re: Tank ventilation.

Yep mix it 50:1, I hope that it is the same in metric system.

 

[DJ]

Re: Tank ventilation.

bigoldboy,<br /><br />Yes, those tanks need to be vented for that engine.

 

[bigoldboy1]

Re: Tank ventilation.

Thanks a lot to Nathan and DJohns for all the help. I will be asking a few more questions on the forum so maybe I will speak to you again.