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#38484 11/15/2004 8:35 PM | Joined: Sep 2004 Posts: 51 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2004 Posts: 51 | I just bought a rebuilt Rochester Model B that has a small hole drilled in the air horn. I was assuming that the hole should not be there until I ran into this on ebay: http://cgi.ebay.com/ebaymotors/ws/e...=4504440863&rd=1&ssPageName=WDVW . It is a Model B with the same hole drilled in the horn that my rebuilt one has. Please look at the upper left photo of the left side of the carb to see the hole drilled in the air horn below the choke shaft. Does anyone know what the holes are for? Thanks for your help. Jon | | |
#38485 11/15/2004 10:06 PM | Joined: Sep 2003 Posts: 2,384 Shop Shark | | Shop Shark Joined: Sep 2003 Posts: 2,384 | | | |
#38486 11/15/2004 10:50 PM | Joined: Jul 2002 Posts: 188 Member | | Member Joined: Jul 2002 Posts: 188 | Well, I can't remember, but somone posted about that a while back. I have 3 B's and one has the same hole. | | |
#38487 11/16/2004 3:49 PM | Joined: Sep 2004 Posts: 51 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2004 Posts: 51 | Thanks Dave & Brian,
I tried to locate that topic in the forum and couldn't find it. Do you have any idea what keywords I should try besides Rochester + Model + B?
Dave, have you tried to run your B with the hole? It seems as if that the hole would cause the carb to flow lean due to the vacuum leak it creates. In addition, I am not crazy about the amount of dust that would be sucked into the hole.
I think I need to plug the hole. However, I am not sure how to plug it. Anyone have any ideas?
Jon | | |
#38488 11/17/2004 12:02 AM | Joined: Sep 2003 Posts: 1,820 Shop Shark | | Shop Shark Joined: Sep 2003 Posts: 1,820 |  My local Ace Hardware store has all different sizes of plastic and metal hole plugs - some are pretty small. A plug like that might work! Or a small piece of lead shaped into a ball the size of the hole, inserted in the hole and held on the back with a tap on the front from a small hammer, to form fit it to the hole. I looked at several old carbs I have here and none of them have a hole in that spot, but that doesn't mean that the hole shouldn't be there. General Motors used several suppliers for their Rochester B Carbs and even though they were "B" carbs there was differences between them. All of them did have an air hole somewhere on the air horn. Most had two air holes, one on each side, or front and back. I can see where it probably is supposed to be there, but you could try to plug it and see what happens. I think you will find it should be open - as a vent.
"Truckin' Around .......... Since 1937!" My name is Joe and I am addicted to Classic Country Music. I just can't hep myself.Operators are standing by to take your calls! Now cruising in the Passing Lane | | |
#38489 11/17/2004 3:16 PM | Joined: Jul 2002 Posts: 188 Member | | Member Joined: Jul 2002 Posts: 188 | The B with the hole was on my 49 w/216 when I bought it. I put a kit in it and it ran ok. I finally ditched it for a carter YF, but I don't think the hole had anything to do with my carb problems(typical B, airhorn warped, running rich). I do remember asking someone about it when I did the kit. maybe call Carbking at his shop, he would know, and seems to be nice to talk to. | | |
#38490 11/17/2004 3:43 PM | Joined: Sep 2004 Posts: 51 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2004 Posts: 51 | Thanks Guys,
I think I'll give Carb King a call. | | |
#38491 11/19/2004 4:03 PM | Joined: Sep 2004 Posts: 51 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2004 Posts: 51 | Thanks to pages 43 and 44 of the "1950 Servicing GM Model "B" Carburetors" manual posted by Keith Hardy, I think I know what the hole is for. Evidently, it was drilled to correct a stalling, rough idling or hard starting when hot problem. Pg 43- http://chevy.tocmp.com/1950carb/50c43.htm Pg 44- http://chevy.tocmp.com/1950carb/50c44.htm Consequently, I think I will temporarily plug it and see how it runs. If it does not have any of the hot problems described above, I will install a permanent plug. Thank you Keith for sharing your manuals with your fellow stovebolt lunatics. | | |
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