Motorcycle Repair: 1965 Honda 50 throttle problems, honda 50, air leaks

Question
My 1965 Honda 50 has a little bit of a problem starting. However, once started it stays running for a while. My problem is with the throttle, full throttle is almost too much and the engine seems to bog down. It seems like the sweet spot with the handle is about half throttle. The bike doesn't want to go faster than about 20 mph before it starts to bog down again. What do i need to adjust or replace to fix this?

Answer
Tony,

-what to fix depends on the condition
overall of the engine. Best bet is to
see what the compression is like as
it will not run well if it is too low.
-If it is over 100 psi you might
be able to improve the running by
making sure all the usual tune up
stuff is done, like spark plug, air
filter, carb clean, points clean and
set to break on "F" mark.
-Set valve clearance .002"-.004"
-The flywheel may have an advance unit
on the back that is stuck and
check the flywheel key as well.
-If this has the auto clutch,
turn the adjuster out until some resistance
is felt, then screw it in 1/8 turn
or so. Lock the adjuster nut.
-Make sure no brakes are dragging.
-check for air leaks on intake/carb connection.
-is fuel petcock clean, fuel flowing well to carb?
-Your spark plug color tells alot
about the running conditions:
http://www.v6z24.com/mods/howto/images/plugs/plugs19.jpg