tank vent question

[joho5]

Well its for my 1989 Evinrude 70hp

Is the vent just automatically always open? From the gas tank, there are 3 hoses...

1. big one for filling the tank with fuel
2. smaller one where the fuel line comes out and connects with the motor
3. the vent line that vents to the hull of the boat.

do I need to make sure and do something to open the vent, or is it just always open?

I am experiencing inconsistency at WOT and trying to eliminate the cheap fixes before I start spending money.

I am rebuilding the carbs today. I have replaced fuel lines in the motor.

I have a feeling its the fuel pump going bad?

also, could this be old gas causing inconsistency.

I just bought the boat and the old owner didnt use it at all last season, so we are looking at a 1 1/2 to 2 years with the gas sitting in the tank.

he said he started it every month on muffs. He didnt mention putting an additive, until I asked and he said he did.

I am not sure he said it to let me hear what I want to hear, or if he really did. I did fill it with 6 more gallons of fresh gas and thats on top of it already having a 1/4 tank of the old gas. Its a 12 gallon tank.

 

[mulishatroop940]

Re: tank vent question

the vent hose should always be open it relieves pressure in the fuel tank and for expanded fuel in case of over filling

 

[joho5]

Re: tank vent question

So if I unplug the fuel main fuel line in the cowling before it goes into the fuel pump or carb and pump the bulb and fuel steadily comes out, the fuel tank is fine as far as the pickup and primer bulb working?

thanks

 

[tashasdaddy]

Re: tank vent question

yes, on the vent, it should have a screen cover, if not kritters will nest there, and clog the vent line. get rid of that old gas. yes, it can cause some of your problems.

 

[joho5]

Re: tank vent question

thanks man, I have a question about these carbs on this motor.

there are 3 of them. at the top where there is usually an adjustment knob on smaller motors its a jet orfice looking thing.

does this thing have to be adjusted or cleaned, or is it set automatically?

and I suppose its just air that passes through this area.

thanks

 

[tashasdaddy]

Re: tank vent question

it depends on which carb you have, early or late model, the early is fixed jets, the late has a mixture screw on the starboard side of the carb. look at them here http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f