The metering rod is pretty sensitive as far as adjustments go, for best results eye ball it best you can and go for a drive with a slight incline and an acceleration ramp. If it really runs good, lower the metering rod .050" and try again. It may take a few tries but you are looking for a lean condition, uneven running, slight engine temp increase, lack of power. When you find this spot, raise the rod back up .030" or so till it just goes away. I use a set of calipers to measure the rod location. Since I have a air-fuel ratio gauge mounted in my truck, .040" difference on dual W-1s will change the air fuel ratio as much as 1.5 points.
Hello and thank you for the replies... If I understand this correctly, It seems that I have two options, find either a CT 109-2 or a T109-25 to set the metering rod or use the trial and error method described by Joe...
In the 1930's, Standard Hygrade had the largest assortment of aftermarket carburetor stuff.
Don't know what happened to Hygrade during WWII, but after the war, Standard Hygrade cut their coverage dramatically.
Carter, and the other carburetor manufacturers didn't really care for Hygrade, and I have several in-house documents where Hygrade parts had been compared to either Carter or Stromberg original parts. The reports were not overly complementary of the Hygrade parts.
Carter tools are, for the most part, readily available. Hygrade tools are not so readily available.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
Philippe, I would go with Jon on this...use Carter tools. Being that you didn't ask, everyone will probably assume you know the proper way to use the gauge.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
All right, I will go with the T 109-25 Carter tool, but actually I have never used one before... I wouldn't mind step by step instructions if you have experience with them... Thank you.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
I'm a novice so the first thing that came to my mind is why do I need this expensive little metering gauge?
The Carter gauge is tapered, at a specific angle, to a point and sits inside the main jet. If you measure from the shoulder of the gauge to the tip of the gauge you will not read 2.795 but something greater. The distance 2.795 is from the shoulder to a point where the taper contacts the jet inside. Needless to say it's not accurate to measure this distance with calipers as compared to using the gauge. If you had a properly set carburetor you could measure from the gauge shoulder to the top of the jet and use this distance as a reference. However, the jet in another carburetor may not be the same height or the gasket below compressed more. In a nutshell, the gauge makes measurement easier and the accuracy better.
Also notice step 40 and 41 of the W1 service PDF.
I may be wrong but there needs to be one more step. Back off the throttle adjustment screw (not idle adjustment screw) so that the throttle valve is completely seated (closed).
The pin of the pump should lightly touch the gauge shoulder. You want to triple check before making any adjustment.
Your carburetor is 80+ years old. If there is wear in your throttle arm, throttle connector rod, pump arm shaft or it's connecting hole then your precision setting may be for naught.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Buoymaker has mentioned one of the "gotcha's" I mention in my blog on the Carter type W-1 carb.
When rebuilding, one should ALWAYS check for wear on the bracket/arm that is affixed to the back side of the throttle shaft, and the rod from this arm that operates the metering rod/accelerator pump. The hole in the bracket arm should be round but wears oblong. The round rod which is inserted into the round hole will over time wear a groove.
Both parts are readily available (although there are different parts for different carburetors) for all W-1's.
Jon
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
You also need a Carter jet and Carter gaskets under the jet and carburetor top for the gauge to be accurate. Aftermarket jet may not have the same taper and gasket may not be the same thickness. Even after setting with the gauge, one should tinker with the adjustment for the best running to account for the different fuel quality of the area.
Thank you for posting the service bulletin... As soon as I get the Carter tool I will give it a go. I have a new arm and bracket that I will use if needed also... Quite frankly, a modern revision of the process step by step with clear color photos would be really helpful...
Creating an accurate step by step with color pictures is labor intensive. It can be done but it's not what today's generation wants.
The modern version is called "You Tube". There are several videos for the W1 out there on the Internet. But just like Forrest Gump warns us: it's like a box of chocolates, you don't know what you're gonna get.
I think the original B&W Carter documentation (rebuild sheets) are intended as steps for the experienced mechanic, of the past, who doesn't need elaboration. Fast forward to today, most service work is done on engines that have fuel injection so there can be a void for local carburetor service.
Most of the carburetor rebuilds today, in my opinion, are done by a varying degree of hobbyists and novices (like me). It's basically cleaning, swapping out a few worn parts, new gaskets, setting up and fingers crossed it all runs halfway decent afterwards. This process works okay for mostly clean (not corroded), not too old, not warped and light to moderately used carburetors, if repair parts are still available.
Jon does professional carburetor restoration. Experience is something you can't effectively write down for a novice to follow or understand. As an example, I have no idea what a new or restored Carter W1 should run like or how it needs to respond when an engine is loaded or at idle.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
The Carter W-1 is an extremely reliable and fairly efficient unit, and adaptable to many engines. There is even a Cadillac V-12 happily running around using 2 of them. And parts and documentation are readily available.
(Opinion) very unfortunate that Carter built the W-2 for only 1 year. Would have solved a lot of issues for the 235 CID engine.
As to the YouTube videos: I have watched maybe a dozen various of these on various carburetors, and came to the conclusion most enthusiasts would be better off NOT watching the videos.
The good news about the internet is that anyone can post. The bad news about the internet is that anyone can post!
The original documentation (opinion) is better than ANY of the videos that I have watched.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
