Carbs or something else?

[ajs350]

Last week my 79 ran like a dream as usual. Today though, it was stuttering at low revs and I put it down to just warming up. But the symptoms continued. It was the same feeling and noise from the engine that you get when you run out of fuel on Main and have to switch to Reserve so that was what I did but with no change. I rode a bit further and the bike ran well above 1/4 throttle but was bogging and stuttering below that. Stopped at a gas station to fill up and it took a full 5 Gallons and that was just to the bottom of the filler neck. That's my problem I thought, no fuel, but as I rode on there was no improvement on either Main or Reserve.
So I'm thinking the fuel got so low I must have sucked in some muck from the bottom of the tank and the pilot jets are now blocked. Before I go taking the carbs off could there be a simpler explanation?
Thanks
Ross

[daves79x]

I'd thoroughly check the fuel tank, petcock filter and then observe fuel flowing freely from the outlet hose to the carbs first. Make sure you are getting a good flow. If that proves out, then you'll need to go deeper. I'm guessing it had something to do with the petcock and running on reserve.

Dave

[ajs350]

Fuel is flowing well from both main and reserve. One thing I noted with my infra red temp gauge is that #6 is running much cooler than the others. I have a spark and compression is at 140psi. Could it be just this carb is having issues? Dirt or stuck float maybe?

[letxbruce]

Maybe a weak spark on that cylinder; perhaps a loose connection somewhere in the plug wire

[daves79x]

Good on the fuel flow. You can easily get #6 bowl off and have a look. See what you find there, then start looking for an ignition issue if nothing carb-related is apparent, as letxbruce said.

Dave

[EMS]

How about if the #6 jets are clogged with debris. The float bowl will be full and the cylinder still does not get any fuel....

[ajs350]

I changed plugs and leads with no change. Took #6 float bowl off but it was completely clean with no sign of any dirt. Removed the jets and gave everything a good blast with carb cleaner. Put it all back together and what do you know it runs a treat. I guess there must have been something in one of the jets that was clogging things up. As always thanks for all of the ideas and help. Ross

[Larry Zimmer]

Good on ya, mate!

[FalldownPhil]

How about if the #6 jets are clogged with debris. The float bowl will be full and the cylinder still does not get any fuel....

Nailed It !!

[EMS]

A blind squirrel finding a corn, Phil...