Rochester model B blues. Please help. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rookierodbuilder · 08-11-2009, 08:49 PM

Hi there, I have a 66' c-10 with a 250 inline six cylinder motor. At one time, I had the truck running but one day it decided to quit and only run if I poured gasoline into the intake manually. I checked the fuel pump and it worked fine. so i decided to rebuild the carb. after checking all my passages if they are free or not, the thing still will not run for lack of fuel. Note: I understand that you have to soak the plunger in oil for the accel. pump to work, (I soaked mine in WD-40) yet it is still not pumping properly. Have i used the wrong soaking procedure, or is there another problem i should check?

neto · 08-11-2009, 10:05 PM

Do you know if there is gas in the bowl? Could the needle be stuck? Just a thought.

Bob Magana · 08-11-2009, 10:26 PM

What about the Vacuum Advance Lines?

skullboydeath · 08-11-2009, 11:33 PM

Alot of things it could be on these old carbs make sure the rubber seal is good on the accel pump if not lubed enough it will tear when you install it . Check the float make sure its adjusted right and no holes are in it. And check the little metal filter that in where the line goes in Every kit i have every bought seems to be missing it. Na make sure you used the right gasket that seals the bowl to the top most kits come with a couple of them and they look almost the some but the wrong one will block so holes

rookierodbuilder · 08-12-2009, 12:50 PM

okay. i dismantled it again and found that there seemed to be a passage above the check valve for the accel. pump, should that part of the gasket be have a hole, or is it there for a reason? Also, if it is of any help it is a model BC to be exact.

ol Curt · 08-15-2009, 09:06 AM

Yes! Some kits have a gasket without that hole. You will need to carefully make one in the gasket or order a new correct gasket.

Eagar1 · 08-15-2009, 12:47 PM

Make sure your throttle shaft does not have too much play, if it does you could be sucking so much air that it won't even draw from the idle circuit.
If you are careful, you can fix this by dissasembling the lower plate, and they make bushing kits, or you can use copper pipe or even JB weld if you are good enuff with it. I would also put a fuel pressure gauge, and or a fuel filter with a glass sleeve or a plastic one that you can see into to make sure you are getting fuel to the carb.
Brand new needle and seats can sometimes stick, with the top of the carb off, let the fuel float drop and look to see if the needle drops, if not, pull it open or blow some air in there, then with it open spray some WD 40 on it and let it sit a bit and do it again. Also make sure your choke is opening. Sometimes when reassembling, the internals can come apart and the choke may look open, then suck closed or stay open, either way it may foul up the starting proceedure.

08-11-2009, 08:49 PM	#1
rookierodbuilder Registered User Join Date: Jan 2009 Location: Sharpsburg, Ky. Posts: 110	Rochester model B blues. Please help. Hi there, I have a 66' c-10 with a 250 inline six cylinder motor. At one time, I had the truck running but one day it decided to quit and only run if I poured gasoline into the intake manually. I checked the fuel pump and it worked fine. so i decided to rebuild the carb. after checking all my passages if they are free or not, the thing still will not run for lack of fuel. Note: I understand that you have to soak the plunger in oil for the accel. pump to work, (I soaked mine in WD-40) yet it is still not pumping properly. Have i used the wrong soaking procedure, or is there another problem i should check?

08-11-2009, 10:05 PM	#2
neto Registered User Join Date: Jan 2007 Location: Madera, California Posts: 291	Re: Rochester model B blues. Please help. Do you know if there is gas in the bowl? Could the needle be stuck? Just a thought.

08-11-2009, 10:26 PM	#3
Bob Magana Registered User Join Date: Aug 2009 Location: Santa Paula, CA Posts: 14	Re: Rochester model B blues. Please help. What about the Vacuum Advance Lines?

08-11-2009, 11:33 PM	#4
skullboydeath Registered User Join Date: May 2008 Location: Johnson City, TN Posts: 45	Re: Rochester model B blues. Please help. Alot of things it could be on these old carbs make sure the rubber seal is good on the accel pump if not lubed enough it will tear when you install it . Check the float make sure its adjusted right and no holes are in it. And check the little metal filter that in where the line goes in Every kit i have every bought seems to be missing it. Na make sure you used the right gasket that seals the bowl to the top most kits come with a couple of them and they look almost the some but the wrong one will block so holes Last edited by skullboydeath; 08-11-2009 at 11:36 PM. Reason: One more thing

08-12-2009, 12:50 PM	#5
rookierodbuilder Registered User Join Date: Jan 2009 Location: Sharpsburg, Ky. Posts: 110	Re: Rochester model B blues. Please help. okay. i dismantled it again and found that there seemed to be a passage above the check valve for the accel. pump, should that part of the gasket be have a hole, or is it there for a reason? Also, if it is of any help it is a model BC to be exact.

08-15-2009, 09:06 AM	#6
ol Curt Junior Member Join Date: Dec 2006 Location: Newburgh, IN Posts: 1,247	Re: Rochester model B blues. Please help. Yes! Some kits have a gasket without that hole. You will need to carefully make one in the gasket or order a new correct gasket. __________________ 1966 Chevy C10 Longbed I'm Bob....ol Curt was my Grandpa The truck was his and he sure as heck wouldn't understand why I took a perfectly good truck and tore it down! Last edited by ol Curt; 08-15-2009 at 09:06 AM.

08-15-2009, 12:47 PM	#7
Eagar1 Registered User Join Date: Sep 2006 Location: Las Vegas, NV Posts: 169	Re: Rochester model B blues. Please help. Make sure your throttle shaft does not have too much play, if it does you could be sucking so much air that it won't even draw from the idle circuit. If you are careful, you can fix this by dissasembling the lower plate, and they make bushing kits, or you can use copper pipe or even JB weld if you are good enuff with it. I would also put a fuel pressure gauge, and or a fuel filter with a glass sleeve or a plastic one that you can see into to make sure you are getting fuel to the carb. Brand new needle and seats can sometimes stick, with the top of the carb off, let the fuel float drop and look to see if the needle drops, if not, pull it open or blow some air in there, then with it open spray some WD 40 on it and let it sit a bit and do it again. Also make sure your choke is opening. Sometimes when reassembling, the internals can come apart and the choke may look open, then suck closed or stay open, either way it may foul up the starting proceedure.



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