Motorcycle Repair: Yamaha Banshee, cylinder compression, fuel inlet

Question
I have a 2000 Yamaha Banshee. One of the pistons is not firing(right side). The engine starts and runs on one cylinder. I have installed new plugs and verified spark on both. While running gas shoots out of the right exhaust.

Answer
Jorge,

first thing to do is see if the cylinder
compression is near the same on both
cylinders. They should have about
125 PSI with a minimum of about 100PSI.
Any lower and the rings or pistons
are needing repair.

If the comprssion seems about equal,
it is likely that the carb float needle
is leaking on the non-running cylinder.
It may just be some dirt stuck
in the float needle valve.

Gently spray some carb cleaner into
the carb fuel inlet or remove
the carb and clean it out.
Try draining the float bowls and
refilling them.

It may also be flooded with fuel and need
some time to clear out and some dry
spark plugs.