OMC fuel tank vent

[ckr74]

I put a OMC fuel tank in my boat a while back and it appears that the venting is not in the cap but by the fuel connector. I did some searching on this and the vent is basically a one way vent meaning it let's air in as fuel is used but won't let pressure escape. I think this is correct. Could a hole be drilled in the top of the tank to add a vent similar to the cap vents? Could the cap be vented? This thing builds a lot of pressure, so much that it leaks by the carb seat.

 

[thudpucker]

What year motor?
Two Hoses or just one?
We have to know those things to help you!
You think your fuel pump is pumping fuel to the Carb so hard, it's blowing by the Carb gasket?

I never heard of that happening.
But just guessing, I'd never want to drill holes in the fuel take for a vent. We have trouble enough with gas fumes as it is.

 

[ckr74]

What year motor?
Two Hoses or just one?
We have to know those things to help you!
You think your fuel pump is pumping fuel to the Carb so hard, it's blowing by the Carb gasket?

I never heard of that happening.
But just guessing, I'd never want to drill holes in the fuel take for a vent. We have trouble enough with gas fumes as it is.

Here's some more info. 1982 Johnson. One hose fuel system. Motor is not running. It's so much pressure that it blows by needle and seat. Hope that makes more sense.

 

[TheMaestro]

I have an OMC tank for my evinrude, and it has pins on the fittings that get depressed when connecing the hose. There are 2 pins, but one went wonky on me at the end of the season, and it would make the engine stop, so I had to loosen the gas cap to vent. This year I went with a new smaller plastic tank with a vented cap. My guess its your tank fittings....also make sure your primer bulb isnt backwards as they are directional...

 

[Pappy]

There are about a million of these engines running out there. No need to start re-engineering the system at this time.
Replace or clean your needle and seat assembly and you should be good to go.
You can typically create more pressure by squeezing the primer bulb than the tank will build.

However you did bring up a point.
Depending on where you (anyone reading this thread) keep your boat it is never a good idea to keep the hose connected to the engine for this very reason.
You can never tell when a piece of debris will get between the needle and seat, start a steady leak, and you come home to a hot garage full of gasoline and fumes from the situation above. Hit that garage door opener and ...............

 

[toofuss]

I have problems with mine building pressure in the heat. If i un hook the like from the motor it will build pressure to the point of seeping fuel out the end of the connection. If i un hook at the tank it will leak into the bilge of my boat.