Motorcycle Repair: CB250 carb problems, honda cb250, improper adjustment

Question
Hi Rich, i have a 1982 Honda CB250 when you leave the petrol tap on fuel comes out of the carbs overflow when the engine is not running. When it runs it does not rev properly and feels flat whan you have it on full throttle when riding. If you ease off it become better and regains some of its power. It has new needle valves as i thought this would cure it and i have adjusted the floats to the correct height. However the problem is still there? Thanks Brett

Answer
Brett, the needles aren't shutting the fuel flow off.  It could be dirt in the fuel line. It could be the improper adjustment or, floats that have become saturated and no longer float.  If the carbs have brass floats, shake them and see if you can hear fluid inside.  You'll just have to figure out what's preventing the needles from shutting off the fuel.  

When this happens, I take the float bowls off and manually lift the float to make sure it will shut off the flow at some point.  If it does it's ususally adjustment.  If it doesn't, there's something in the needle or seat causing the problem.

Regards
Rich