Motorcycle Repair: 1997 Honda 600 f3 power problem, fuel delivery system, fuel contamination

Question
Good day,

I am experiencing problems with the power/accelaration with the bike.  The bike will start and run but there is no power/torque.  This problem happened before and all I did was drain the fuel and put new fuel in and the problem went away after I ride a few miles, but now its not going away. Do you have any suggestions?

Answer
Modern sport bikes are really not my forte' but based on your brief description, it sounds like you have a fuel contamination problem. If the bike has been sitting for a long time, with old gas in the system, then the whole fuel delivery system needs checking. Replace the fuel filter, too.

Try to drain all the carburetor float bowls and see what comes out by catching the fuel in a small container. If there is water/dirt or old varnish, then the carbs need a good cleaning.

If the carbs are clean, the problem could be with the spark module controls, perhaps it is dropping two of the four cylinders under power or there is no spark advance, which is all electronically controlled. Be sure that the battery is fully charged.

Yamaha makes some carb cleaner that you can funnel down the carb rack, let sit and then drain again. Follow the directions.

Bill Silver