I have a Zenith L63 Carb which needs to be replaced but I have some questions when looking at the replacement carbs. 1st - the 2 Zenith carbs I found look exactly like the one I have but they have no model numbers stamped on them or tagged. Should I buy a carb based on the same manufacturer and looks only?? 2nd - the 2 carbs I am looking at have 1 major difference and I was wondering what people thought about the differences. 1 carb has plug which is where the main jet is. The 2nd carb has a valve which you can adjust the main jet. Which one is better to use?? Additional info which confusses me a bit: The owners manual for the engine shows the carb to be used as the non-adjustable main jet (plug at the bowl end). But the engine has the adjustable type (valve at the bowl end) which was working OK for the past 3 years until I broke it. Should I lean towards what I have and worked or what the manual states? Wisconsin engine model #VH4D See attached pics of the 2 carbs Thanks for any help Leckster
I'd go with the ajustable model. As long as the throttle plate and mounting flanges line up correctly. Kind of like pre emmission control versus post "you can't adjust anything" emmission standards.
Welcome to HEF Leckster! :drinkup
HELLO COUNTRYBOY!i HAVE A QUESTION ABOUT A MODEL 33 ZENITH CARB ON A 1998 Z45/22 GAS/LP FORD 423.I REBUILT IT,INSTALLED IT,RAN OK FOR FEW MINUTES THEN MY WORLD HAS NOT BEEN THE SAME SINCE.THE ELECTIC CHOKE WAS NOT REPLACED.WHEN I START THE MACHINE I HAVE TO USE MY FINGER ON THE CHOKE PLATE AND KEEP IT CRACKED OPEN JUST A HAIR OR IT WILL RUN REALLY ROUGH.WHEN USING THE MACHINE DOES THE ELECTIC CHOKE MAKE MINOR ADJUSTMENTS ACCORDING TO LOAD OR HYDRAULIC USE?I WOULD NOT THINK SO BUT I HAVE TO ASK.OR DID I SCREW UP THE REBUILD?PLEASE HELP,THANX GEO
carberator: french word for don't screw with it... if it only runs with partial choke, you need a bigger main jet. Howard
Isn't that the truth. How did the engine run before the carb rebuild? What makes you think the carb is/was the problem? This is running on gasoline, right? Have you checked for vacuum leaks, before or after the rebuild? The choke does not adjust based on load, it should be wide open pretty quickly after start up, can't remember exactly how long. If it ran alright when you first started it up, and now when you start it cold it runs rough from the start (while the choke is still on), then I'd pull the carb apart again and check the jet for plugging, or remove it if that's the style.
Generally speaking the choke should be adjusted so that the choke plate is just closed when cold. Should be a vacuum pulloff that opens the choke some when the engine starts, maybe a 1/4" or so. As Delmer says usually only takes a couple minutes for the electric heating element to fully open the choke. The choke is adjusted by loosening the three screws and rotating the unit. Make sure the vacuum hose is connected and you have vacuum at the end of the hose when the engine is running. YMMV
Those 4D's are good engines. The first post-use the adjustable main jet model. Second post- If it only runs with choke partially closed-#1 float to low #2 main jet partially plugged #3 vacuum leak. But it sounds like you have the electric choke adjusted too tight. As soon as it starts the vacuum should crack the choke open. Set choke so air horn plate has a 1/16 to 1/8" air gap. The electric choke should be wide open in a two minute span depending on the ambient temp. Truck Shop
Check the choke shaft air seals, on a carb the will only run with the choke on...