how do i drain the carb on a crf100?

Answer 1

there should be a small plug at the base of the carb. unscrew it, and the gas that's in the bowl will drain. put something underneath that area first, and unless u want to become extra crispy, only do this when the engine is cold.

Answer 2

by looking at the diagram, it doesn't appear the CRF100F have the little access cap in the bottom of the float bowl... which would be the easiest way... but since it doesn't, you will need to loosen the rear clamp (that holds the carb to the air filter box boot) and the front clamp (that holds the carb to the boot to the cylinder)... once these are loose, rotate the carb to where you have access to the three (usually 4 on most bikes, but the diagram shows only 3 on this bike) small screws that holds the float bowl (the bottom part of the carb) to the carb housing. the float bowl should come off with little effort...

merely reverse to re-install insuring that the gasket between the float bowl and carb housing is in place.

http://houseofmotorcycles.bikebandit.com/parts/Honda/CRF100F/2005/1199609 for a diagram of how it fits together.

Answer 3

Looking at the picture pmk provided, there is a drain screw.
It's the screw right near the "#5"
Loosen it and the fuel will drain out the hose on the bottom.
Put a clean cup underneath so you can see what kind of junk came out (if any).