I've been fiddling with my daughter's 57 chevy with a 235 and if it sits for a day or two it's super hard to start - The old Rochester B that was on there would start up but it was leaking from everywhere and dumping fuel in the intake (so it actually started but ran super rich and was a fire hazzard). I bought a reman carb and the thing doesn't want to start up cold no matter how much pumping of the accelerator or cranking I do. It's like there is no accelerator pump action - the only way to get it to start is to manually squirt fuel into the intake and then crank it up - once I do that it fires almost immediately and will settle right in to a nice idle. Does the Rochester "B" have an accelerator pump? Any ideas on what to check or what they might have done wrong with the rebuild (and unfortunately it's been over the 90 day warranty so I'm not going back and buying another one only to have the same problem) - FWIW there are new plugs, wires, cap, rotor, set timing, checked advance, choke closes when cold - just won't start without a shot of fuel. I'm almost tempted to try the 2bbl sniper EFI setup on an adapter plate if I can't get this figured out. Here's pics of the carb that I bought from the parts store website - it looked about identical to the one that came off... Nrc117-2 by bwiencek posted Dec 16, 2018 at 7:23 PM Nrc117-1 by bwiencek posted Dec 16, 2018 at 7:23 PM
Float bowl size vs. evaporating fuel. Simple as that. A larger fuel bowl takes longer for todays alcohol (alcohol evaporates faster than gasoline) enriched gas to evaporate vs. a smaller bowl. Time for an electric fuel pump. This will cure a few situations dealing with todays gas. Mike
Yes choke works (I said near the bottom: "choke closes when cold") - everything works fine except I'm making a guess that either the float level is way low or an accelerator pump issue?? Not sure about these old carbs....
Maybe the throttle plate is not closed enough to create a good vacuum.just a thought..good luck with it
I've gone round and round a couple times with these Rochester carbs. I'm no expert, and I never had your particular issue, but maybe I can help a little. First, maybe get 'er started with a shot of fuel as you've been doing and let 'er run for a minute. Then shut 'er off and see if the accelerator pump is working...a nice strong stream. If it does, we know it doesn't have an enlarged prostrate. I mean, the pump is good...and the problem is elsewhere. If it's still not working, I'd pull the top off the carb and inspect the accelerator pump...especially the rubber to see if it's ripped or possibly even installed incorrectly. (kind of folded over as it was inserted) Also...if I remember correctly, there's a ball-type check-valve in the bottom...directly under the pump? Or near it? Be careful...the spring and ball can roll away, never to be seen again. Just to be clear...the spring won't jump out, but you can easily dump/spill/drop them. I'm thinking that someone might've forgotten to install the check-valve ball and the pump is just pushing fuel back into the bowl. I hope I'm not leading you down the Primrose path. I've been guilty of it before. But my intentions are good...lol. Let us know.
Mike, I've actually tried an electric fuel pump - one of those small MrGasket 12S pumps - so I know it's got fuel into and filling the carb - I've tried with the fuel pump and without. Since it starts and runs great after a shot of fuel is in it and idles perfectly on the choke and kicks down when it warms up and drives OK (a little flat spot when hitting the gas until it's warmed up a bit (which also makes me think accelerator pump / fuel level) I'll have to try that - I'm usually so fed up with trying to start it after I have to pull the stock oil bath air cleaner to prime it and put it back together then start it that I haven't looked at that - I'll leave the air cleaner off next time and check and see what's going on. I'm going to guess that I'm going to have to pull apart the reman carb that I just paid good $$ for to fix what they messed up - You may be on to something with the missing check ball or one that doesn't seat/seal and thus can't pump fuel. (Anyone know a paper filter that fits under the stock 57 chevy 210 hood? So I can get rid of the bulky and messy oil bath air filter)
the easiest way to sort out the Rochester B is to "Bin" it and run a Holley 1 barrel off a 200 Ford with an electric choke conversion. Or a Carter Y series With a Holley 1 barrel it will be like a night and day improvement all round. [driveability and economy]
I can see how the oil-bath air cleaner would make a minor carb problem a bit of a hassle. Patience, grasshopper.
Rochesters can be a pain. I don't know what your issue is, but they can be prone to warpage. I have a 60 235, and had trouble with a couple of my Rochesters. I ended up going with an auto choke carter YF. They're common, easy to rebuild, and pretty much bulletproof.
Literally millions of these vehicles ran with a 235 with this carb......and are still running with it in all sorts of configurations. If you are looking for a reason to do a 2bbl EFI Sniper double pumper whatever......go for it.....but I think you are missing something basic with the stock setup. Too late at night to do a diagnosis,but will try tomorrow.
I've read a bunch on this and other sites and man are there conflicting info out there as to what carb is good and will work and won't require major mods to make work... I'm going to stick with this one for now until I hit a point where I can't sort it out - then I've got to decide which way to go (and whichever way it will either be an easy conversion or I'm going EFI...) I've already got an electric fuel pump and have let it prime and have pressure up to the carb's fuel inlet (I can open the line at the inlet and fuel runs under pressure)
I just spin the engine over a some before hitting the gas,if I let my 37 (57 235) sit a couple weeks the fuel evaporates so it has to spin to get gas back up in the carb.
The conflicting 'pinions (ork-ork) are because it's a fact...these carbs have a couple or three inherent issues. And just as some say that all flatheads are prone to overheating or 6V electrical/charging systems won't charge at idle...if the component is serviced and adjusted correctly...including these old Rochesters...they'll work quite well as intended. So some will give up and call a component junk, while others will take the time to make it right. Sometimes it's a challenge. Sometimes it's worth the effort, sometimes not. Depends on the person and the application.
FWIW in case anyone runs into this one - I worked on it today again and turns out the float level was just a little low (so it didn't fill up far enough) and really the main cause on not pumping was the delay spring on the accelerator pump - the lever went down and compressed the spring but the plunger never hardly moved at all. Put a little more preload on the delay spring and it's now moving and pumping fuel properly and starts cold with just a pump of the throttle to put some fuel in it and set the choke and then just turn the key. The real test will be after it sits for a week or so and see if it'll fire right up. Jon - thanks much for the offer - think I've got it figured out but if it's still not solved I'll ring you.
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