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Got the 51 out of cold storage today, now that Spring has finally hit Montana. The car is running great, lots of power and pickup until it starts getting warmed up well. Then when you hit the throttle it sputters and almost dies until you back off on the throttle just a bit, then it smooths out. The trick is that accelerating gradually won't cause it, but heavy acceleration will. The carb was rebuilt two years ago (about 500 miles or so), but the problem has been with me for longer than that. I'm guessing that the carb has some problems, or maybe the fuel pump. Any suggestions?

I can think of a few possibilities but for a starter is the distributor vacuum advance functioning?

No - if I remember correctly, the way to test it is to remove the copper line and attach a hand operated vacuum pump to it and see if the arm moves. Is this correct?
thanks

That would be a good test, but you could try something even more fundamental - just apply a vacuum with your mouth and see if it holds the vacuum.

Also look down the carburetor (with the engine not running) Choke open all the way and work the linkage to the carburetor and you should see two streams of gas with each full movement of the linkage. (Do it fast like when you stomp on the gas pedal for best results.)
Wes

Tried the suction test on the vacuum advance and it failed. Looks like I'll be sending it off for repairs. Side question - I have a spare off a 50 288; anyone know if it is the same as the 51? I'm thinking about having them both done at the same time, so I'll have a spare.

If they are both from the same manufacturer, then probably interchangeable. The difference comes with the springs and shims used inside the chamber to regulate the action. Others may know more about this.

Instead of having yours rebuilt why not just exchange them for already rebuilt units? Max, Terrill, Kanter, and others have rebuilt units for exchange.

(o{}o)

Well, did some investigation this afternoon. A 1950 Delco distributor(model 1110811 9K20) has a grease cup on the side, a 51 doesn't. The 50 vacuum advance is a model 1116041, with the number 344 stamped on the arm. The 51 is a 1116060, with the number 158 stamped on the arm. The earlier model also has a right angle brass fitting on it. The fitting has restrictive ports in it. On the 51 version, the restrictions are in the body, and isn't a right angle. End of story, have to get a new/rebuilt one before the old girl will run right.

I did run a vacuum test on it again, using a hand pump. Absolutely dead.
Bummer

FYI - Terrill Machine, 1000 County Rd 445, De Leon TX 76444 rebuilds the advances for $75. Sending it off today. They don't advertise in Hemmings anymore, but I've bought lots of engine parts and services from them back when I lived in Texas.

I sent the vacuum advance off to Terrill this morning for rebuilding, and put the 1950 version on as a temporary fix, so I can at least move the car. Lo and behold, it seems to work fine. I'll take it out for a long test drive later this week.