All:

I tried to fired up my 2006 883 Sportster over the weekend and it wouldn't start. I noticed I was pretty low on fuel, so I added a little extra fuel to the tank and it started right up on choke. I got it to the gas station and filled it up with gas. It started up perfectly after that, I figured my problem was solved. About 30 seconds later, I'm sitting at a traffic light and I hear my RPM's drastically rev up to about 2500, then, the bike died. I haven't been able to get it to start since. Anyone have any idea what might cause this problem? I'm thinking I need a new fuel filter. Any other suggestions? All help is GREATLY appreciated.

Thanks!
Bob

 

check the vacum hose on the petcok. If it does not have a vacum it will not flow gas to carb.

 

You could try tapping the float bowl with the handle of a screwdriver. If the float valve is stuck then that might dislodge whatever is causing it to stick. If that works then you need to replace the screen above the petcock at the bottom of the tank. You might as well replace the fuel line since it likely has gunk in it as well and clean the float bowl.

That would explain running out of gas or getting fuel out the overflow. It has a float valve pretty much like a toilet to maintain the fuel level in the float bowl. That would not explain revving though. Revving would take, at least, a richer AFR like opening the choke. More than you could do with the choke would take more air as well. You should check the VOES and throttle operation. One thing would be whether the engine actually increased or the pitch changed. If you kicked into a higher advance due to a problem with the VOES then it might sound a bit differant. If you sprung an intake leak it might change pitch as well. If it could get fuel with that intake leak then it might actually rev, but it bypassing the jet so you would have to have fuel pooled in the intake. The only way I see that is the accelerator pumping spraying it in, but it's a bit hot out for that.

Overall I can't explain the revving. You seem certain it ran out of gas so the float valve sticking seems likely. The likely cause of that the screen in the bottom of the tank. The rest is just a wild guess as to why it might have revved or seemed to.

 

Thanks guys, this is very helpful!