Hitchcocks Forum

Hi, I have a 2009 500cc bullet efi and i cannot seem to stop the plug from getting really sooty and black. Can you adjust the mixture? If so how and where...? The plug could only be in for 5 mins of running and it is black.. Any help would be grateful I have not had it long. thanks Franky

That's the classic sign of a "Rich Mixture" ie}--Either too much fuel OR Air starvation..Basic things first, like have you checked the Air Filter and the airflow into the injector body ??...Don't get too technical too soon BUT it might be a sensor on the blink...."Ambient air" could be the suspect one as this might be the fuel enrichment staying on OR partly on after start-up.........

Thanks Alan, all iv'e done so far is changed oil and the air filter and oil filter and it does run a lot better but the plug is still sooty. I just wondered if there was a way to adjust the mixture. I will try what you said though thanks..

Is the "sootiness" dull or shiny?

Thick and dull.....

Have you checked that it is the correct plug?.

Yeah the plug is correct thanks, Alan is the sensor the rollover sensor or the lambda sensor??

From what I've read on here the efi is particularly sensitive to the type of plug used. Perhaps fellow owners can advise of the best make and grade?

Hi Frank, just read on another forum someone having exact same problems, turns out he was running a NGKBPR6ES and I think thats what i have in. Should I go to a Bosch and a hotter plug? Or which is the right plug??

Check that the enricher cable (choke, but not really a choke on left hand handlebar). Make sure it is seated well at the bar and at the other end on the throttle/injector. Check it also has free play...