How Long Should I Let Fuel Stay in a Carb?

How long should fuel be allowed to sit in the carburetor of a motorcycle, ATV or side by side? You could probably let it sit for a month, but not much longer.

Partzilla’s powersports pro John Talley goes live on our YouTube channel every Friday at 3pm Eastern to answer your motorcycle, ATV and UTV questions. In this session, John gives his thoughts on how long you should allow unused fuel to sit in a carburetor.

How long should fuel sit in carb

How Long Fuel Should Sit in a Carburetor

How long would you allow fuel to stay in the carb? I typically let my machines sit for a couple of weeks before I recycle them and don't drain the bowls.

John Talley: Well that’s actually the best way to do it. I mean, you can go ahead and drain the bowls, but there’s always going to be a little bit of fuel left in there anyway. It’s almost impossible to get everything out unless you break the carb all the way down. The best advice is, yes, you could probably go a month, but don’t go past that. You want to make sure, if it’s at all possible or available, to use non-ethanol fuel, because that stuff phase separates and all the junk heads down to the bottom. And of course that’s the first thing your carburetor is going to pull in when it separates like that, and it’s not if but when. Ethanol is the bane of existence for boat owners because the boat typically sits for a good period of time in between uses. But I wouldn’t want to let it go more than a month, even with an ethanol fuel. Do what you’re doing, which I think is probably the best, plus that’s also exercising your battery on occasion.