I have a 954 that seems to be running rich. The bike will start hard and idle rough. Black smoke will puff out of the pipe, especially after letting off of the throttle. These are the the reasons I think it's running rich. It's fuel injected though, so I don't know where to start, and it isn't throwing any codes. I thought of having a valve adjustment and throttle body sync done, just to see if that was the problem, but it acts like it's actually getting too much fuel. At higher rpms, it acts normal. Any ideas? Anybody run into this before?

 

If your at a pretty high rpm, then just dump the throttle off, it can puff some black smoke. Your engine is pulling in a lot of fuel and air, then when you quickly shut the throttle off, it closes the air inlet, but the injectors have still dumped fuel in for a split second. You get a split second rich condition. Its normal to get a little black smoke when you do this. Some bikes do it more than others, but its not uncommon. However, if its a lot of black smoke, you may need an adjustment.

Try letting off the gas a bit slower and see how it reacts. If it doesn't do it, your more than likely ok.

If its doing it just idling or at first start up. You may have a problem with your enrichener. Possible in the ECU or a faulty Fuel Pressure Regulator. Or, you may just be in need of a new set of plugs. A cold engine and an enrichened (choked) engine are hard on plugs, and very noticeable with bad plugs.

Also, does the bike have a Power Commander on it? If you bought the bike used, its possible that someone doesn't have the correct map for it.