4 mechanics ( 3 pros & Me) have worked on this for aboyr 30 man hours. Looking for any thoughts...
FOrk lift is 25 years old and alsways has run fine til now
Starts very easy
each cyclinder is 150 psi
No smoking
Cleaned spark plugs
undid exhaust pipe to bypass muffler ( thought might have been plugged)
Changed gas
cleaned carb and jets ( were not plugged)
cleaned butterfly under carb
replaces points, condensor,rotor cap and rotor
replaced plug wires and ignition coil
fuel pump seems to pump fine ( disconnected and throws gas fine - assuming filter is clean)
adjusted carb settings ( back to orginal now)
ran 2 cans of carb cleaner thu tank
throttle linage works fine - opens fine and fully open
Nothing we did has changed. After idle - rpm stays the same
Airfilter is removed

Runs great at start and idle. JUST will not increase RPM.
Thanks for any suggestions