The Ford Barn

Mercmarc · 11-01-2021, 01:17 AM

Hello All,

Has anyone run across a lean mis fire under light throttle condition with new model 94's from Dennis Carpenter? Jet sizes from 49 to 62 and power valves from 5.5 to 4.5.

Background:

New 1950 239 built by Mike of H&H with the 94's on it. Ran well on the engine stand. Driving under light throttle just off idle to 1500 RPM it bucks, lean on the throttle and the bucking stops.
Parked in the garage you can raise the rpm and choke the carbs slightly and the engine speeds up slightly, even with the jets at 59.

Idles well, runs well under moderate to heavy throttle, plugs are still brownish.

Many thanks for any input, solid wires, HEI and point distributors, autolite plugs have been used with no change.

Respectfully

Marc

11-01-2021, 01:17 AM	#1
Mercmarc Member Join Date: Aug 2017 Location: Roseville, Ca Posts: 84	Lean MisFire Hello All, Has anyone run across a lean mis fire under light throttle condition with new model 94's from Dennis Carpenter? Jet sizes from 49 to 62 and power valves from 5.5 to 4.5. Background: New 1950 239 built by Mike of H&H with the 94's on it. Ran well on the engine stand. Driving under light throttle just off idle to 1500 RPM it bucks, lean on the throttle and the bucking stops. Parked in the garage you can raise the rpm and choke the carbs slightly and the engine speeds up slightly, even with the jets at 59. Idles well, runs well under moderate to heavy throttle, plugs are still brownish. Many thanks for any input, solid wires, HEI and point distributors, autolite plugs have been used with no change. Respectfully Marc