Spark Plugs are Black

[SeaMarshal]

I recently returned from a coast to coast trip and thought the gas mileage was not where it should have been. I pulled the stock plugs which had about 20,000 miles on them and they were black (too rich?).

I was running the bike hard on the way home, and ended up using gas w/ethenol a number of times.

Thoughts from the gang?

[ArthurKnowles]

Sound like it was running rich to me. I don't know how many miles you have on the motorcycle, but my '06 with 18K on it was also having poor gas milage (in comparison with others) so I decide to repalce the O2 sensor. I'm sure the original was still working well enough not to be considered defective, but repalced it anyway. My gas milage went up 3 ~ 5 mpg on the spot.

I'm not sure where it is at a reduced pace. My initial tests at 75 was 40 ~ 41 mpg with 10% ethanol premium fuel. I took a trip this weekend at 85+ that dropped it down to 35 mpg.

I replaced the O2 sensor on my RT at 61K as it was only getting 30 mpg. Afterwards the gas milage jumped to 41.3+ mpg at 75 mph (actual verified with GPS). I suspect if I keep it down to 65 ~ 70 I might get 45 ~ 50 mpg. But it is so hard to keep my hand on the throttle from rolling on the speed!