Backfiring through S&S carb...

[JoeShovel]

Have a 66 Shovel with S&S shortie super E carb setup. The other day I was riding and everything seemed fine but then after I went to the gas station and I filled up with 89 (have been using 93 for the last few months) she started to run like crap and backfire through the carb. Could it be that I switched to a lower octane even though I used to use this octane before. Nothing else changed and she ran fine up until that point. Plugs were black.

Checked everything else and everything was fine.

[JoeShovel]

Maybe I should of stated I'm from the states... I didn't realize until later that this was for Great Britain. I hope I can still stay and receive some help...

[grbrown]

Originally Posted by JoeShovel

Maybe I should of stated I'm from the states... I didn't realize until later that this was for Great Britain. I hope I can still stay and receive some help...

Hi Joe,

Your simplest way ahead is to drain the fuel off (put it in your car?) and refuel with higher octane, such as you used previously. Hopefully that will answer your question, by it running right again. Run the bike for several miles to make sure the carb is running on the new fuel. Don't adjust anything until you try that!

[45Brit]

Originally Posted by JoeShovel

Maybe I should of stated I'm from the states... I didn't realize until later that this was for Great Britain. I hope I can still stay and receive some help...

the name is the give-away...