Looking for complete adjustment/tune up info for a Carter W-1 carburetor used on a 1948 Chevrolet Fleetline Aerosedan.

Try this document HERE.

Excellent Information!!!! Thank you for sharing it!!

Daryl
Just sent you a PM

Besides following the recommendation in your manual, and other articles like the excellant one in Daryl's post another important part to rebuilding your carb is the tools you choose to do the job. Always use a tight fitting screw driver tip. If you do not have one go out and buy screw drivers to fit your screws or grind the tips down on the screwdrivers you have to fit snugly. I also have ground the sides off of one of my screwdrivers to accommodate removal of the inlet and outlet check valves and the nozzle screw.

The best screwdrivers have shafts on them that allow you to use a Crescent wrench to turn the screwdriver to remove the screw. I always prop the carb against my large vise so it does not move while I am putting maximum downward pressure on a screw head. I then turn the screwdriver with the Crescent wrench. You will hear a popping sound when the screw lets go. That is music to your ears.

I work on a clean white tagboard surface so I can see the parts easily as I remove them or they fall off. The inside of a yard political campaign sign works great. I place each part in a white plastic meat container as I remove it, the kind you get from the grocery store with your hamburger.

I also use a needle point electrical pliers to take off all the small clips. Try to be very careful when removing the clips, they bend easily and like to fly away. You will soon find a good name for the clips when they fly off somewhere and you can not locate them. An old timer called his "Jesus Christ" clips. I call mine "Dammit" clips.

I just took apart a carb I brought home from a salvage yard last week. Fortunately, it had no rust in the entire throat except for a frozen up throttle valve. I got some used transmission fluid and soaked the entire carb in it a couple of days. I lightly tapped on the ends of the throttle lever and finally it came a little loose. I then tried to open and close the throttle valve using the lever and it finally moved. I kept it well lubricated as I continued to work it loose and now it works like it was brand new. I have found that if the air filter is left on the carb, the carb does not seem to rust up so much. So if you are walking through a salvage yard and the filter is still on the carb you will probably find a salvageable carburetor.

I do lightly sandblast the worse rust and grime off the carb and also soak it in carburetor cleaner according to the recommended time on the cleaner. Usually, half an hour is recommended. My gallon can of cleaner is over 10 years old. It recommends rinsing the carb in water and wire brushing off any remaining grime.

I hope others will also comment on their best practices. I still have a lot to learn about all the reconditioning procedures.

Good luck, Mike

Torpaero,

If you need one I have an extra all metal genuine Carter 25-33 needle and seat. According to the carburetor gurus gasoline with ethanol added attacks the rubber tip needles.

If your throttle shaft is loose bushings for Rochester Quadrajets are an ideal way to restore a proper fit. A snug throttle shaft vastly improves idle quality because idle air is coming through the carburetor orofices rather than along the throttle shaft bore.

Ray W

Would the Rochester Quadrajet bushings referenced in an earlier post that were used to repair a loose throttle shaft on the W-1 have a part number? And can they be purchased individually?

Thanks, found it myself. Quadrajetparts.com if anyone's interested.

While needle-nosed pliers can be used for removing the spring clips (pin springs); there is a MUCH better tool available from Snap-On.

I don't know the name of the tool or the number, but the tool is a small brass tube approximately 6 inches long with a spring-loaded clip retainer on one end and a push button on the other.

Push the button, and it opens the retainer on the far end, allowing the rebuilder to grasp the pin spring. Releasing the button then causes the retainer to close and locks the pin spring to the tool. The pin spring can then be installed or removed as necessary. Once the operation is complete, pushing the button will unlock the tool so the pin spring is released.

The tool is relatively expensive for what you get (about $16. the last time I checked), but if you rebuild carbs and count your time for anything (the time lost when looking for the dropped pin spring), it is the cheapest tool you will ever buy!

As to throttle bushings:

The design tolerance from the throttle shaft to the throttle body is 0.004~0.006 inch. An additional 0.003 will not cause problems. Check the clearance with a dial indicator. If the clearance does not exceed 0.009 inch, no machine work is necessary. If the clearance does exceed 0.009 inch: 999 times out of 1000 it will turn out to be a worn throttle shaft. Of the hundreds of W-1's I have rebuilt, I have YET to see one that required bushing!

MUCH more common to need to replace the clamp on throttle arm on the back side of the throttle shaft and the "L" shaped rod that connects this arm to the countershaft arm.

The most common issue with the W-1 that bites the sometime rebuilder is the clogging of the horizontal idle cross passage at the top of the cast iron casting. Very small passage, and if clogged, the idle circuit will not function.

And if you feel you absolutely MUST place bushings in the throttle body NEVER use a drill bit (use an end mill) and NEVER mill clear through the throttle body. Doing so will leave an internal vacuum leak that will prevent a proper idle being obtainable. No offense meant to anyone, but this operation is a machine shop operation to be done by a machinist with a good milling machine! Just as important to the operation of the carburetor as boring the block is to an engine rebuild!

Jon.

Ray - no offense, but ethanol is harder on steel needles than it is on modern soft-tipped needles:

http://www.thecarburetorshop.com/Steel_needles.jpg

Jon.

I am going to install points on my '47 Fleet Master (first for me). I understand that the points should be open in order to set the correct gauge (.017 I think). I think I can bump the starter until I get it on top of a lobe, then check the gauge. I do not think it is necessary to have it on TDC, but I just wanted to know how to determine TDC.

thanks
rsh47

To determine TDC, remove all of the spark plugs. Put your thumb on the number one cylinder. Bump the engine over until the compression on number one cylinder blows your thumb off of the spark plug hole. The timing mark should line up near the pointer. Once the timing mark is even with the pointer you are on TDC. The rotor on the distributor should also be pointing to the number one tower on the distributor cap.

Thanks for your reply. This sounds like simple way to determine TDC.

Thanks
rsh47

Isn't the timing mark at 5 deg before TDC. I believe TDC is labeled as UDC on the flywheel.

"Ray - no offense, but ethanol is harder on steel needles than it is on modern soft-tipped needles:"

Good morning Jon. No offense taken. In fact, just the opposite. I really appreciate your knowledge on the subject. My mistake was accepting as fact an oft stated opinion on this forum.

I have a home machine shop and I have put bushings in W1 throttle shaft bores using a long reamer to get a true hole all the way through and in the hole in the float bowl cover that the accelerator pump/metering rod bell crank shaft rotates in.

Thanks for enlightening me on the needle/seat issue.

Ray W

I just turn over the engine until the points open. Then with one hand turn the rotor (there is about 1/4"of free turning) so points are open the greatest amount and with the other hand measure the gap with a feeler gauge. For new points use .021" for the gap for new points as the gap will lessen with use. Also coat the cam lobes with a film of grease to prevent too fast of wear down of the rubbing block.
The timing should be reset after installing points as a change in gap changes the timing.
TDC has no effect on the gap because TDC does not necessarly mean the points are open at their widest.

If a commitment is made between you and your car ....... not to leave one another, take the time to purchase the reprint of the GM SERVICE MANUAL for your specific year Chevy.

YOUR car will thank you.

When I wanted to find exact TDC I bolted a degree wheel to the damper. Then I had a broken spark plug with a bolt threaded down through it that would hit the top of the piston. I put this plug in number one and turn the engine by hand till it stopped. Then mark the wheel and turn the engine the opposite way till it stopped. Half way between the stops is TDC.

When I took Auto Mechanics in High School ( I won't say the year, but the dinasauers were gone!) we were taught that with the valve cover removed, turn
the engine over and watch the rocker arms on No.6 cylinder; No. 1 and No. 6 cylinders are 'running mates', so,when No. 6 cyl exhaust valve just closes,
No.1 is on top dead center compression, with both valves closed! There is no way anything can get damaged this way, and it is extremely accurate!

Hi

When rebuilding the W-1, what's the consensus on using the copper washers or using a small amount of "Blue" Loctite instead to prevent air leaks?

I use the copper washers as they have 100% resistance to gasoline either with or without ethanol. Some sealers may be gasoline resistant but not ethanol. I don't know about "blue" Loctite?

I appreciate your input Chipper.

Anyone ever have issues with idle jet not sealing after removing it? I read up that when new it was squared off at tip and gets tapered as you tighten it down to make the seal.

I've been watching this real neat YouTube channel where this gent has wonderful videos on mechanical work done to his 48 Fleetline.

Here is the link to his W-1 rebuild.

The "low speed jet" is or should not be reused because it is an ait tight fit in the opening That being ssaid I have resuse them with no problems.

You beat me to the punch! I was about to correct myself and put down the correct part name of "low speed jet". Glad to hear you've had no issues. I hope I run this luck too! Yeah.....I was very curious about this and was thinking maybe I run a pick in the top of the tapered end to flare it out a bit so it would reseal again.

I would not advise that.

Flaring the end of the low speed jet has been suggested in the past. I typically don't have problems with the jet seating when flared with a blunt ice pick. Have even used a think coat of solder on the tip and only occasionally found any benefit for a sure air tight fit.

Thank you for steering me in the right direction.

I was reading the Shop Manual and it sounds like if the Low speed jet was installed new, they had you remove it to make sure it had a "bearing" taper on the end of it. If it did, sounds like it was good to reinstall.



On another note, I just found the metering rod adjustment gauge on ebay and got it for $24, looking forward to using this to make sure the metering rod is sync'd up properly after my rebuild.

Hopefully I purchased the right one, its the T109-25

T109-25 is the correct gauge for the Chevrolet W-1 metering rod adjustment.

Great news!

Thank you so much guys!

Both slightly flaring the end of a used low speed jet to make it seal, and using blue loctite instead of the copper washers were taught to me by the Headmaster of the Carter Carburetor School. Have used both for decades with no problems. Carter Sales Division suggested not reusing the low speed jet because they put new low speed jets in their carburetor kits, and of course, wanted to sell the kits.

For those that want to use the copper washers, I have no problem with that, and include them in our rebuilding kits; but I don't use them.

Jon.

I greatly appreciate your input. I will keep everyone informed with pictures and hopefully a nice video of the rebuild. Now I just need to find the time to get this done.

Thank you Jon!

I finally found the elusive Carter T109-25 Metering rod gauge!