In Reply to: Re: 9N w/ INCREASED HP posted by Larry Holbrook on August 23, 2018 at 10:24:48:
There is no real advantage to a Zenith other than they make your tractor run.
The Holleys were overly complicated, cranky, difficult , cold blooded and sucked to boot.
After 40-50 years the pot metal vacuum piston and bore are worn out and the bore isn't replaceable short of a new carb.
Whenever I get one I like to do my best Tom Brady impersonation and give it a heave into the nearest swamp, scrap pile or dumpster.
The Holleys probably did give you a few more horsepower hours per gallon of fuel but I will gladly forsake that better efficiency for a tractor that runs sweetly.
I'm not an advocate of dumping a good ol MS carb on an N or Hundred but the Holleys are past their use by date.