hi. recently one of my friends bought a CBR. he complained that when he pickup from the 2nd gear there was some kind of loss of power. so we removed the carburetor to inspect first and then clean.

surprisingly we could see some metal sheets wrapped around the float just above where the float plunger touches the float . mixture screw settings were 3/4 out in all 4 carbs!. we already know that these float heights are not adjustable and mixture screw settings are totally wrong. anyway jet sizes were ok and they were in stock sizes. we removed those metal pieces and put it to the standard screw settings and balanced. now the bike runs fine.

But can someone explain what that previous owner / mechanic had done to this carb ? what is the purpose of those metal pieces wrapped around the float ? what it could have done to the float level and fuel supply overall ? and why is that pilot screw settings are totally out. we checked the plugs. one plug is ok and other 3 had kind of black carbon soot on them.



thank you.