I have a 98 Sporty with a custom stretched tank. The tank builds up pressure because the gas cap only vents inward and the tank vent has been welded (brazed?)shut. From what I can find on this forum the tanks come that way new and you have to drill out the vent plug if you want to hook up the stock vent system. Sometimes when the tank has too much pressure I get leakage out of the carb drain hose. I can circumvent the problem by burping the cap before I turn on the gas but I really would like to have the tank vented normally to the charcoal cannister. I am thinking of drilling the vent out without removing the tank. But suppose there is some gas in the vent tube? One thought was to put a little water in the tube from the top. Any gas would float on top of the water. Then I could use my Dremel tool flexible extension to carefully drill out the vent. I would have to drill very carefully and slowly and use oil to keep the bit cool. When I get water leaking out I stop. Might be good to plug the top end of the vent tube also.
So what do you think? Is this safe? Or am I going to blow myself up?
Anybody else have to deal with this? Any other ideas?

 

builds pressure or creates a vaccuum?

 

gas under pressure=danger

 

Make sure your homeowners insurance is paid up.
Seriously though, you need to drain the fuel before doing any kind of work with power tools. The dremel emits sparks from the motor area. Bet ya didn't think of that now, did ya? 8-)

 

+1 And let the tank air out for a day with the cap off to evaporate any leftover traces of fuel and fumes.

 

Why use power tools? Is everyone in the world too lazy to consider using their
hands anymore?

Why not chuck up an 1/8" drill bit into a tap handle and drill the brazing out by
hand.... no motor = no spark... the brass is a soft enough metal that it shouldn't
take too long to cut through it by hand like this.

Gazza

 

It builds up pressure. Maybe due to sun heating up tank?

 

Great idea. I will give this a try. Hopefully the plug is brass or solder. Thanks...

 

Warning, warning will robinson

 

Use EXTREME caution when ever you are using ferris metal tools around flammables. Drain the gas and Fill the tank with water. Keep an extinguisher close at hand and work out doors.