Honda 2000 not drawing gas from aux fuel tank

I found the problem, thanks to you guys. Missing an O-ring at thr aux tank fitting.

Could be you need to trade it on a Champion.

Could also be leftover high volatility winter gas at high temp and high altitude.

good news is the honda sips gas even at full throttle. Bad news is it sips gas, so even a extremely small vacuum leak will keep it from pulling from an aux tank.

There are two possible causes. First did you open the vent on the aux tank? If not that's the likely problem.

If not, a vacuum leak.

Every time I or others I know have had trouble it was a vacuum leak or forgetting to open the vent on the aux tank. And searching for one is pretty much a lost cause. Not drawing fuel is the symptom and for us it was solved by checking the lines for tight connections, and most often a leak on the gas cap. Some aftermarket kit caps are much worse than others for not sealing well.

Altitude shouldn't be an issue. I've run ours at 7000+ft no problems.

How do you search for an air leak? Must be really small.

Air leak.

When filling the Honda tank, those wonderful no vent gas cans that press against the tank opening can damage the surface allowing air to leak in. Check that the gas cap has a perfect sealing surface.

Damdifino wrote:
I've got the classic aux tank setup with Honda 2000 attached to a 6 gallon marine fuel tank using marine fittings. This has worked perfectly for two years. Going off its own tank, the Honda runs like butter. This week, however, the Honda just isn't taking up fuel from the aux tank. I've checked everything I can think of. I'm camped at 5200 ft if that might have anything to do with it. Usually I'm at sea level.

Well you have some experience using this, so from my experiences with nearly the same setup, are the Honda and the tank about level? I try not to have my gas tank much lower than my Honda. Those fuel pumps can't be very strong, so I try to not make it work too hard. Also, make sure you have no air leaks. Not even a tiny one, they will not work then. As far as altitude, I live at 5500' so like I said, nearly the same setup.

Oh yeah, is the marine tank vent open? Just checking.