I am having problems with my idle- rich lean -rough etc. I pulled the carb apart and noticed that the Idle mixture screws poke through the bores in the base. (I screwed them in further for the picture). Is this normal? I Compared it to an older 2g and there were no holes in the bore aside from two little ones above the screws, The screws did not go all the way through. This carb is from 1971- GM 307. Thanks for the input.
The baseline to start with is usually 1-1/2 turns out on each and go from there. You will want to take your fizz can of carb cleaner and make sure that the idle passages are clear before putting it back together.
Thanks Mr48. Im just curious if those passages are supposed to go all the way through the bore in the base plate
Yes. I have several old rebuilts in boxes and none of the tips stick thru like yours. With the springs on and the screws all the way in I can barely see the pointed end of the screws thru the base, they are not coming thru like yours.
Thanks! Maybe thats the problem. The holes are stretch too big from someone *cough* screwing them in too far. or they could be the wrong mixture screws
For some reason I'm thinking that the 307s had an odd carburetor all of their own in some ways. Think the throttle bores were noticably smaller than the 2GCs used on 327s and 350s. Wonder if a previous owner might have put it together with the wrong idle mixture screws, and possibly other pieces as well. Might explain the problem you're having of getting a steady, proper idle mixture.
Looks like someone really overtightened the screws, I had a base like that and the screw had actually broke out the iron around the idle hole.
It is common to see this when the screws have been over tightened. the cast iron base is then where the point of the screw passes into the body. Try some new idle mixture screws you might be able to make it work
While we are talking Rochester 2bbls ... could someone explain the difference between a Rochester 2G, 2GC & 2GV. ??? (Mine are 2GV without chokes...the only reason I know that is because that's what the supplier said when I purchased them) Also, where in the world is the best place to buy replacement parts? I've been trying to locate some nylon gaskets that go behind the brass nuts @ the fuel line intake fittings. (This is the fitting/nut that gets removed when you replace the fuel line filters) The nylon gaskets are like oil pan drain plug gaskets, but slightly larger in diameter. I only need a half-dozen or so, and suppliers like Automotion, Hot Rod Carberation, etc. - have a $50.00 min. order. All the local parts stores, dealerships and even Summit Racing Equipment have been unable to help. Any suggestions?
Tripple G I would try Vintage Speeds website. He may have the nylon gaskets and no minimum the last I looked.
Thanks for the info. I've been looking at buying a rebuild kit off ebay. Someone is selling Rochester 2bbl Carb Kits and even though my carbs are new, I thought it might be a good idea to have one in the spare parts box. They list 3 different part numbers: #96-111D, #96-346 & #96-259A. All say they are for all 3 models. They very in price from $18 to $27. I don't want to spend more than I have to and want to make sure I get what I need. The kits are made by GP Sorensen (Guarenteed Parts Co.)
Tried several in the area, NAPA, Advance, Auto-Zone, etc. NAPA Stores run hot & cold, some good - some bad. The ones around here can't find anything unless it's in the computer. In fact, that's true with ALL Auto Parts Stores anymore. If they have to look in a parts catalog - Forget It! What happened to the good-old-days when parts guys knew parts? Before you answer...I know, economics, you get what you pay for and that includes counter help. Thanks to the H.A.M.B., found exactly what I needed. Vintage Speed is the way to go.
Just got a kit from oreilly - Walker part# 15512A- http://oreillyauto.com/site/c/detai..._-1&keyword=carborater+kit&pt=02447&ppt=C0359 Napa has them too- just look under 70s GMs or Chevys- i.e. 1971 Chevelle 350. I ordered a crap load of parts from Vintage Speed over 2 weeks ago, havent seen or heard anything yet.
Just wanted to let everyone know, Vintage Speed had everything I needed. Placed my order online August 26th and received order complete on September 6th. I thought that was pretty good service.