B Carb Issue?

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My B fluxuates at low idle. I checked the governor and took the play out of the linkage. The rpms will vary without the throttle shaft moving. I replaced the manifold gasket and carb to manifold gasket. It runs fine from one third to full throttle, but when I try to run slow cultivating or am watching it idle, it won't stay at one speed. Any suggestions?

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Scott(SC) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Starr, SC Points: 397	Post Options Post Reply Quote Scott(SC) Report Post Thanks(0) Quote Reply Topic: B Carb Issue? Posted: 09 Aug 2012 at 7:55pm
	My B fluxuates at low idle. I checked the governor and took the play out of the linkage. The rpms will vary without the throttle shaft moving. I replaced the manifold gasket and carb to manifold gasket. It runs fine from one third to full throttle, but when I try to run slow cultivating or am watching it idle, it won't stay at one speed. Any suggestions?

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Chalmersbob Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Pennsylvania Points: 2122	Post Options Post Reply Quote Chalmersbob Report Post Thanks(0) Quote Reply Posted: 09 Aug 2012 at 9:18pm
	Do you have the "anti-surge" spring in place? It is a fine spring that attaches in a hole in the carburetor link rod and the other end attaches to a manifold stud. LOL Bob
	4 B's, 1 C's,3 CA's, 2 G's WD, D14, D15, B-1, B10, B12, 712S,

Scott(SC) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Starr, SC Points: 397	Post Options Post Reply Quote Scott(SC) Report Post Thanks(0) Quote Reply Posted: 09 Aug 2012 at 9:36pm
	It does have the spring. I did hook it different so that it took up the play in the linkage.

Steve in NJ Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: Andover, NJ Points: 11994	Post Options Post Reply Quote Steve in NJ Report Post Thanks(0) Quote Reply Posted: 10 Aug 2012 at 6:42am
	Sounds like its running a tick on the lean side or, a vacuum leak somewhere. Pull the choke on just a little bit and see if the engine smooths out and behaves itself. If it does, then its one of the two I mentioned. Could be a piece of debris in the idle circuit also, but try the easy stuff first. Fattin' up the mix a tick with the air/fuel mix screw and see if there's any change. Another thing I do if I suspect debris in the idle circuit is bring the rpms up to 3/4 throttle, and then stick the palm of your hand over the carb and quickly open the throttle wide open, then pull your hand away before the engine stalls. If there's a small piece of debris in the idle circuit, you may get lucky and make the engine vacuum draw it out. If the idle doesn't drift up n' down anymore with the choke blade wide open, you succeeded in drawing any debris out of the idle circuit and it should be okay... HTH Steve@B&B

Gerald J. Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Hamilton Co, IA Points: 5636	Post Options Post Reply Quote Gerald J. Report Post Thanks(0) Quote Reply Posted: 13 Aug 2012 at 9:15am
	Sometimes the fluctuation is from idle mixture adjust being leaner than the transition or power range. If there's a power screw it might help being leaner. If its transition and the idle lean isn't from Steve's causes (which are perfectly possible) it could be that the float level is letting more gas in the float bowl and that makes the transition richer. So the engine speeds up more than the governor is calibrated for when the speed changes and then the governor closes the throttle, too much and it oscillates. Gerald J.