This is a bike of a friend of mine, He called me telling me his bike is back firing and carrying on and said it wouldn't rev up (terrible throttle response) was idling high, well the first thing I found was he needed a battery. Secondly he had a MAP sensor code, changed it, still no throttle response and what little there was it was very sluggish, now im starting to think bad gas? he said it was from last year and it was non ethanol fuel. could it be the TPS? I don't want too sound like a parts changer but im at wits end. I looked at the plugs and with it having a fair amount of idle time they were on the rich side. He has no mechanical ability what so ever. May be a broken wire to the MAP sensor since the code will not clear, im only getting the codes from the odometer. What do you guys think? can ya get me in the right direction??? The dude wants too ride.

 

Since you pulled codes already you need to see what they correspond to.

 

I did that it comes up with a MAP sensor I changed that already and the code don't clear. I checked for an intake manifold leak(spraying carb clean around it) didn't seem to have any effect on the idle. Could it be a TPS (throttle positioning sensor) ? He had a bad battery and changed it. It almost has the symptoms of bad gas too. not sure what way to turn since I covered the basics. Any ideas? oh this is my old user name that I had written down and found after I started a new account.