Run with choke on - why?

[Jim Wieringa]

I have a 1966 2000 with Holley carb. Why does it need the choke pulled out to run it's best? Push the choke off and the tractor dies. What do I have to look for? Thanks Jim
 

[Larry NCKS]

Either it has a vaccuum leak, or your carb needs cleaned/overauled. The latter is more likely!
 

[3000OH]

Long-known issue. Search the archives for Holley (or its alt spelling). Some swear by 'em, some at 'em. Count me in the latter. Bit the bullet some years ago and bought a Zenith for our '65, zero problems since then. But others like those H-carbs. So do yourself a favor and go back and read both sides of the story.

Have a good holiday.
 

[Jim Wieringa]

I had the tractor running nice and smooth with the choke on and took a spray bottle with soap and water in it and sprayed every place I could think of and it made no difference in the running. So I guess I can deduct that it is needing a carb kit eh!!
 

[Jerry/MT]

What were you hoping to see with soapy water?

Try spraying starting fluid(CAREFULLY!)around the throttle shaft, the carb to intake manifold interface, and the cylinder head to manifold interface. if you heaar the engine speed up, you"ve found your leak. look for vcracks or rust holes in the intake manifold also.
 

[JMOR]

[TimInd]

Another way to find a vacuum leak is with a bottle of propane, not lit obviously. Let a small amount of propane leak out on go over the obvious places where a leak could occur. When the engine speeds up, that's it.
 

[3000OH]

As for a carb rebuild, some here say that it should only be a genuine CNH kit, not some aftermarket. You may find a seized/corroded accel pump piston.

BTDT before I tossed in the towel on the Holley. Not cheap to do. CNH does not stock replacement Holleys for 2000/3000/4000, only the Zeniths.
 

[kgrove78]

sounds like it needs rebuild i have done several holley carbs for customers and neighbors i use kits from napa or tsc some have been running for several years since. not overly complacated to do. and i use carb clean to look for vac leaks safer than starting fluid with same results. good luck.
 

[DaveH IA]

Also check for good fuel flow from tank-- and I think there is a filter on the fuel pump, Might not be getting fuel to the carb ?? just something else to check