Carb rebuild time?

[bmohan55]

I have a Rochester B on my '72. The truck runs great most of the time but is a bit finicky on starting, needing to use just the right amount of choke and slight throttle blip to get it to catch. If not up to operating temp it will sometimes stall out if I de-accelerate to a stop too quickly.

Today it started fine but about 500 yards away it started bucking and died. It would re-start for about 5 seconds (full choke) then die. After about 20 minutes of this and generous application of carborater cleaner it finally smoothed out and ran fine. I took it home and road my bike to work.

I'm thinking a carburetor rebuild is in order?

Thanks,
Bob

[shortbutslow]

Funny - my Weber 34 ICH acts like this, which is why I'm planning to replace it with a Rochester B!

In looking for Rochester B rebuild info I've found the following if they're of any use to you:
http://www.classictrucks.com/tech/0802ct_rochester_carburetor_rebuild/index.html

Relating to dual setups but has other good info:
http://www.thecarburetorshop.com/RochestermultipleB.htm

[bmohan55]

Here is another link on the Rochester with some helpful links at the bottom of the page

http://www.expeditionlandrover.info/landRoverFAQ/FAQ_rochester.htm

I opened the carb up over lunch and it looks pretty clean (started right up before I tore into it) but since the rebuild kit was only $17 at NAPA I'll rebuild it. Not suprisingly there is no float and level setting listed in the kit for the 2.25 application. does anyone know what the best settings are?

thanks,
Bob

[greenmeanie]

I would start by doing a full tune up with timing, ignition mixture and idle. I say this as it is the only way to give yourself a proper baseline to start diagnosing from.

It sound like you may have a fuel delivery issue. I would have a good look at the usual fuel system culprits for blockage. Then again, for the <$20 it costs for a rebuild kit it can't do any harm to go through the carb. Check what jet size you have as IIRC the Niehoff kit I got was about a 52.

For float level settings I think I looked at the instruction sheet and chose the engine with the closest displacement and used that. I then tweaked from there.

I live in a very mild climate which helps but my 71IIA 88 starts on the first crank as long as I pull full choke. No throttle required. She also pulls like a train (Comparitively - it is a Rover) up to about 60mph

[bmohan55]

Greenmeanie,
Thanks, I should have stated this but I have already gone thru the whole fuel delivery system. New tank, lines, filter, pump, also new alternator, points, condenser, rotor, cap, plugs and wires. Once the truck starts it really runs great, I did over 200 miles on it last weekend. I did have decaying fuel lines so I'm thinking that some crud may have gotten in the carb and still is giving me intermintent problems, but I really don't fully know (yet) how a carb functions. I think the rebuild will be a great learning experience...along with everything else I've gone thru!

Thanks for the advice on the float settings, makes sense.

Bob

[derek]

resurrecting an old post, what is the correct float levels for the rochester in the series

[derek]

Found the answer on the mendo mailing list.


1 3/4"


http://chevy.oldcarmanualproject.com/carb/Rochester/9C308p03.htm

http://chevy.oldcarmanualproject.com/booklets/5020mts00.htm