The Stovebolt Site Forums The Shop Area Engine Shop CARB HELP!!!!!!

I got a 54 chevy truck with the 235. I had a carter YF carb on it that worked fine, I had a rochester rebuilt and installed to see if it would perform better. It has idling issues. running at high RPM it seams to be fine but it acts like its leaning out when you try to let it idle, not getting enough gas. All the passages are clear (unless i missed something). Cant figrue it out. ??????

does adjusting the idle fuel screw effect it at all?

no, just runs real bad from 1200 RPM down, roughly runs for a moment then dies

1. minor vacuum leak
2. float is too low
3. spark is retarded
4. possible bad valve/not seated/bad adjustment

Well, i just stuck my old carb back on. Im tired of messing with it, so IT UP FOR SALE now.

the thing is my other carb works just fine, then i try the other one and it dont work right.

Was the vacuum port on the bottom blocked by the gasket? This will cause them to run rich. A correct base gasket has a slot to expose the port to vacuum. Most gaskets have slots, but not always in the right place.

I made sure that was cear, vacume was fine

I was hoping to see an answer here, I have the same thing with my 216 and Rochester B. I traded in my old Carter W-1 for it and cant get the Rochester to idle smooth. It runs smooth with the choke pulled out a little

Tomorrow I will pull the intake manifold off again to make sure I didnt miss a vacuum leak.

thanks for the ideas here,

Before you pull it apart start your engine and check for a vacumn leak by spraying some Berrymen around the bottom of the carb gasket or the intake /exhaust manifold. If there is a leak it will speed up and you can see it suck the fluid in. You will save your self some work too. I had a split fenaolic block base one time and it gave me the fits trying to find itas it was on the back side. There is one other thing you might check to see if the throttle arm bushing are leaking you may need to replace them.
62Blue
Don

Thanks Don, unfortunately I've been down that road a few times now, I also tried propane, but no affect on engine RPM. This weekend I attempted to seal (tighten up the internal bearing surface on the throttle valve) with some 3M as a test, but no real difference.. I'll keep trying, need to check the timing again and I just purchased a vacuum gauge..

I've also been looking around for a Carter W-1 again.

thanks again

oldblue,
Don't know if you're trying to keep it original or not. I have a have a 261 with a rodchester and it ran poorly, I purchased a holley/webber from Tom Langdon and can not believe the difference it made.Starts right up, idles smoother, great throttle response.
You may want to look into this swap.
Langdons stovebolt.com

good luck

How about this for answering a really OLD post. Just a FYI for anyone struggling with rebuilding the Rochesters.

last year I tracked down a Carter W-1. I was able to purchase a new re-build from an early 40's.

on first run the truck ran like a sewing machine, smooth as silk. It doesnt have quite the stomp I had with the Rochester, but really love this Carter.

I just went through the same thing (as Beast 54) with my '65 Chevy 6 cyl. With the old Rochester carb it ran ok. Truck only had 49,000 original miles and but needed a tune up. The old gal needed to be run and give me some confidence she'd get me down the road. I had a friend rebuild the Rochester. When we cranked the engine she would only run in high rpms, wouldn't idle, and ran hot. First indication was a manifold leak. Did all the checks, nothing could be found. So then I borrowed a Rochester carb from a friends pick up, installed it, and the 6 cyl ran smoooothe. Put the rebuilt Rochester back on, same problem.

I purchased a Carter YF. Truck runs good again. From my reading up about the Rochester carburetor, it only has four screws that bolts it together. (Carter has 6). The Rochester carbs are notorious about warping. Some say they're junk then. It doesn't make sense. But that's my understanding.

Also found out the Rochester accelerator pump uses a leather diaphram. Carter a nylon diaphram. If engine is not run periodically and allows the fuel to dry out (several times) in the Carter the diaphram will crack with the ethanol gas of today. The leather diaphram of the Rochester would be a better choice. And personally I would prefer the Rochester but a professionally rebuilt Rochester can run into some high bucks.

Glad you have a runner.. my Dad (who owned the 42 Jeep on my site) was a motor seagant during WWII. (recently passed away in 08. He had said the army prefered the Carter W-1 and that is about all they used. Tough as nails. I try to keep fresh gas and some stabil in my bowl..