Carbs dumping fuel!

[nvmike24]

I was out this afternoon on the 84 and made a few stops. I went to start the engine and suddenly fuel is pouring out one of the carbs. Couldn't tell which one. Carbs are new, under 300 miles. Had to switch needle and seat assembly's for gravity feed system. I have noticed fuel smell in the garage on occasion but no puddles. Ambient temp was about 110 plus here in Las Vegas and I had been in some slow traffic. 20 minutes parked prior to incident. I am suspecting venting problem and possible Petcock leaking causing the pressure required to unseat the needle.

Any thoughts I have missed?

[Harvy]

Sounds right Mike.......were you parked on the sidestand? Probably tank pressure built up and the fuel came out the lowest (left side) carb overflow because of it.

Hope that's all it was mate. Check your fuel cap venting.

Harvy

[rktmanfj]

I was out this afternoon on the 84 and made a few stops. I went to start the engine and suddenly fuel is pouring out one of the carbs. Couldn't tell which one. Carbs are new, under 300 miles. Had to switch needle and seat assembly's for gravity feed system. I have noticed fuel smell in the garage on occasion but no puddles. Ambient temp was about 110 plus here in Las Vegas and I had been in some slow traffic. 20 minutes parked prior to incident. I am suspecting venting problem and possible Petcock leaking causing the pressure required to unseat the needle.

Any thoughts I have missed?

Yeah.

My '89 had the same issue, and after a long time we finally figured out that fuel was seeping thru the joint where the fuel filter bracket is brazed.  

Had to pull and flush out the tank and re-braze the joints to fix it

Check the bottom side of the tank for anyplace the paint may be flaking away.