The Stovebolt Site Forums The Shop Area Engine Shop Carter YF Rebuild and Tuning

...So I decided to rebuild my carb. It's quite obviously a Carter YF on my 216, but which one? There is no tag, and the numbers cast into the body don't lead anywhere.

I get a kit for a standard YF used by GM over the years. All the parts seem to fit and do their jobs, except maybe the float valve. I tried to set the float height and drop, but I sure had to bend the tabs to get the numbers right. I'm guessing I didn't, as the truck runs worse now than before....

Normally you folks are warning about vacuum leaks and how they screw with performance. Well, hunting for a possible leak in the wiper motor, I removed the vacuum hose from the manifold. The engine sped up and ran more smoothly. This with the idle mixture screw all the way in. I'm guessing the float is over-filling and flooding the engine. I'm also getting some back-blast through the carb and white smoke from it when I shut down, none of which I had before the rebuild. Oh, and it won't run with the choke close at all.

Here are some pics of the carb before the rebuild. I thought either the 2207 number (on the left side of the float bowl) or the 165S (on the front of the float bowl) might mean something, but I can't find those numbers. Anybody know what model this is? And would increasing the float height help with the flooding?

Thanks.

http://inlinethumb06.webshots.com/44229/2038962850057214886S600x600Q85.jpg

http://inlinethumb42.webshots.com/44201/2040714440057214886S600x600Q85.jpg

Does the needle and seat look to be the same as the old ones? If I remember right, my kit came with two sets and one was quite different. Id guess if you had to change the float height quite a bit, then Id pull it apart and recheck everything since it was probably 'close' before adjusting.

Increased float height would mean that it would flood, since as the float height travels upwards it drops the needle letting more fuel into the bowl.

Good luck, Jeff

The kit came with 2 needle-and-seat sets, one solid and one spring-loaded. The one that came out had a spring, so that's the one I used. It looked taller than the original... I'll compare them when I take it apart today.

When I said I'd increase the float height, I meant with the air horn upside down, as when checking the setting. I'm hoping that keeping the fuel level lower in the bowl might help with the mixture issue...

Wish me luck.

The two different needle sets were different heights. The spring-loaded one is about 3/16 taller that the solid one, but the solid one is the same height as the original needle.
I also found I didn't get the original seal out. It came out when I pulled the new needle seat. I set the float height to 15/32 and the drop to 1 1/4, as the instructions said. I think it still runs rich, but I'm having ignition problems now (fouled plugs due to rich mixture). I cleaned them and will try again later tonight

Can anybody tell from the pictures which model of Carter YF I have?

Recheck the float level. With the spring in the needle & seat you just let the weight of the float rest on it. Check the float to make sure there is no gas in it. If you dont get the diaphram on right on one of those you can get a rich mixture.

many times the carb p/n is stamped on the flange that sticks out from the carb body directly above were the throttle rod comes out of the carb base

Well... It wasn't ignition trouble (or not just ignition trouble). I figured I'd try to do a complete tune-up. I got new plugs and wires, and I decided to check the valve motion and lash before I put all the new stuff on, so I pulled the valve cover.

Hmmm.... Shouldn't all the pushrods contact a rocker arm? Why is that one not playing nice with the other parts? No. 2 intake pushrod is about an inch from its rocker. Time to pull the side cover. And everything else in the way.... The rod is bent about 20 degrees, about 2 inches from the bottom. I guess my next check is for a stuck valve.
Does anyone know a quick check to see if it's still stuck? Or do I have to pull the head and get the pros involved? Can I buy just one rod, or do I have to change all the rods and lifters as a set?

Boy I'm glad I tried to get my carb working better....

Thanks for the help
Peter

Take a sledge and tap the valves dead on from above. This means removing the rocker arm assembly. If they seem fine and move easily, then adjust the valves a little loose and spin the engine over. This way you probably wont break and rocker arms or bend any more push rods. Id start with watching the valves that bent the pushrods.

I bent a piece of steel square stock and beveled one end, added a rubber bumper, to act as a fulcrum against the firewall and slide that over the starter lever. This way I can spin the engine over from the engine compartment and watch the valves move.

If you do have stuck valves, spray them down with your best wd40 (or whatever you prefer) and tap them with a sledge a bunch of times. This should free up any stuck valves eventually. You may have to do this several times, keep spinning the engine over slowly before firing her off to make sure they arent sticking.

Jeff

Back to the original issue of the carburator if I may. I too am also looking at mine which by the pictures from Highflyer, looks exactly the same. Also "No Tag". Numbers seen on the Carb are YF, 1-630, 0-824, 6-723. My research also led no where. I would like to know exactly what this carb model is to possible order a kit, and also know what yrs. this was used on. Thanks, Tom

You are looking for a "stamped" (recessed, not raised) number, ending with the letter S as in (S)am.

http://www.thecarburetorshop.com/Carburetor_ID.htm#IDCarter

All casting (raised) numbers are meaningless.

Some of the aftermarket carbs were identified by tag only. Once the tag has been removed, the ONLY method of identification is to measure and compare all machined castings against the original blueprints. Cost to do so will exceed the value of any model YF.

Jon.

I'll clean it up some more and keep looking on it for what you are describing. Thanks Jon for your help, Tom