2 barrel rochester deal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**longblue72** · 05-31-2011, 10:19 PM

Got a to barrel feeding my 350. idles fine and starts up good and all, but when I go to give it gas, it bogs down. Pops told me it was the accelerator pump. So when I go to replace this, should I remove the whole carb? Or take off the top half and replace it from there. Im just wondering whatever was easiest for one of you guys.
Thanks!

bobs409 · 06-01-2011, 07:01 AM

For a quick fix like that, I usually just take the top part off. As long as your comfortable doing that (hanging over a fender) LOL then go for it.

truckster · 06-01-2011, 02:47 PM

It kind of depends. What's the overall condition of the carb? In my experience, by the time an accelerator pump needs attention, the whole carb could use at least some cleaning and gaskets.

**longblue72** · 06-01-2011, 04:29 PM

well i was gonna do what bob said and just replace the accelerator pump, but now my dads gonna take it and 2 other carbs to get rebuilt.

**longblue72** · 02-18-2012, 11:26 PM

bringing this thread back to life, I got the carb rebuilt, and its doing the same thing, if I were to mash the gas, it just wants to bog down, then fire up. would that be my timing thats off? what would I need to do to correct this bogging?

MikeyMan · 02-19-2012, 06:17 AM

Check & inspect your fuel lines and fuel pump.

I have heard of instances where a rubber hose will collapse and restrict fuel supply.

rsavage · 02-19-2012, 06:44 AM

Timing could be the issue.

68gmsee · 02-19-2012, 10:26 AM

Need more info.

What year engine?
How many miles on the engine?
Have you replaced any ingnition parts like points, plugs, rotor, cap, etc?
HEI or points distributor?
When it bogs does it bog during normal acceleration or only on rapid acceleration?

**longblue72** · 02-19-2012, 02:47 PM

I guess year would be a 72
87,653 miles or close to that
Replaced plugs and plug wires
points distributor
And it seems too occur at both types accelerations, id have to come back on tonight and really make sure if it is both

Wrenchbender Ret · 02-19-2012, 05:04 PM

With the engine off, look down the throat of the carb & work the throttle linkage. You should see 2 squirts of gas going into the throat each time. If so the accel pump is working OK. If it is just a dribble your pump is still not working.
Try setting the timing up a little. It is possible the float level is low. The carb may have been changed at one time & the main jets are too small.

68gmsee · 02-19-2012, 05:57 PM

Check the above and also make sure you are using manifold vacuum. The vacuum line below the throttle butterfly valves.

While you're at it, using mouth suction, see if the vacuum advance moves freely, the points are at around .019 at the high point of the cam and the distributor weights also move freely.

**longblue72** · 02-20-2012, 10:39 AM

So that bog is a backfire up the carb. timing?

05-31-2011, 10:19 PM	#1
longblue72 Active Member Join Date: Feb 2011 Location: ellicott city maryland Posts: 152	2 barrel rochester deal Got a to barrel feeding my 350. idles fine and starts up good and all, but when I go to give it gas, it bogs down. Pops told me it was the accelerator pump. So when I go to replace this, should I remove the whole carb? Or take off the top half and replace it from there. Im just wondering whatever was easiest for one of you guys. Thanks!

06-01-2011, 07:01 AM	#2
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	Re: 2 barrel rochester deal For a quick fix like that, I usually just take the top part off. As long as your comfortable doing that (hanging over a fender) LOL then go for it. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

06-01-2011, 02:47 PM	#3
truckster Registered User Join Date: Jan 2001 Location: Orem, Utah Posts: 7,978	Re: 2 barrel rochester deal It kind of depends. What's the overall condition of the carb? In my experience, by the time an accelerator pump needs attention, the whole carb could use at least some cleaning and gaskets.

06-01-2011, 04:29 PM	#4
longblue72 Active Member Join Date: Feb 2011 Location: ellicott city maryland Posts: 152	Re: 2 barrel rochester deal well i was gonna do what bob said and just replace the accelerator pump, but now my dads gonna take it and 2 other carbs to get rebuilt.

02-18-2012, 11:26 PM	#5
longblue72 Active Member Join Date: Feb 2011 Location: ellicott city maryland Posts: 152	Re: 2 barrel rochester deal bringing this thread back to life, I got the carb rebuilt, and its doing the same thing, if I were to mash the gas, it just wants to bog down, then fire up. would that be my timing thats off? what would I need to do to correct this bogging?

02-19-2012, 06:17 AM	#6
MikeyMan Registered User Join Date: May 2008 Location: S.W. Chicago, IL. Posts: 317	Re: 2 barrel rochester deal Check & inspect your fuel lines and fuel pump. I have heard of instances where a rubber hose will collapse and restrict fuel supply.

02-19-2012, 06:44 AM	#7
rsavage Registered User Join Date: Aug 2009 Location: Alden NY Posts: 2,705	Re: 2 barrel rochester deal Timing could be the issue. __________________ 1961 C1 Corvette 1959 El Camino 350 TPI, 9" 4 w disc 69 Blazer K5 - sold July '20 2021 Durango RT 5.7

02-19-2012, 10:26 AM	#8
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 2 barrel rochester deal Need more info. What year engine? How many miles on the engine? Have you replaced any ingnition parts like points, plugs, rotor, cap, etc? HEI or points distributor? When it bogs does it bog during normal acceleration or only on rapid acceleration?

02-19-2012, 02:47 PM	#9
longblue72 Active Member Join Date: Feb 2011 Location: ellicott city maryland Posts: 152	Re: 2 barrel rochester deal I guess year would be a 72 87,653 miles or close to that Replaced plugs and plug wires points distributor And it seems too occur at both types accelerations, id have to come back on tonight and really make sure if it is both

02-19-2012, 05:04 PM	#10
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: 2 barrel rochester deal With the engine off, look down the throat of the carb & work the throttle linkage. You should see 2 squirts of gas going into the throat each time. If so the accel pump is working OK. If it is just a dribble your pump is still not working. Try setting the timing up a little. It is possible the float level is low. The carb may have been changed at one time & the main jets are too small.

02-19-2012, 05:57 PM	#11
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: 2 barrel rochester deal Check the above and also make sure you are using manifold vacuum. The vacuum line below the throttle butterfly valves. While you're at it, using mouth suction, see if the vacuum advance moves freely, the points are at around .019 at the high point of the cam and the distributor weights also move freely.

02-20-2012, 10:39 AM	#12
longblue72 Active Member Join Date: Feb 2011 Location: ellicott city maryland Posts: 152	Re: 2 barrel rochester deal So that bog is a backfire up the carb. timing?



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