Attached is a picture of one of the needles from my 72 SU carbs. I'm worried about the bend at the bottom. I was very careful lifting the cylinder out and don't think I did it, but I guess that how it happened probably doesn't really matter right now

So what do I do now? Try to bend it back? Ignore it and put the carb back together after I clean it? Replace the needle? (I've heard that they are hard to get...)

Daniel

Ouch, well I don't think it is going to work like that! You could try to bend it back but I doubt that you will ever get it back to straight or maybe even straight enough to work right again....

Scott bruning (PO of Z Therapy) had a trick on his old tune-up video. Stick the big end of the needle in a hand drill. Then, using a nice, soft towel, run the needle against the towel. This will cause the needle to bend back into shape. You'll need to spin the needle pretty fast, but not at top speed of the drill.

I've used this technique on needle from motorcycle carbs and it has worked well. It won't cost you anything to try it except your time. If it doesn't work, the needle from Z Therapy aren't that expensive. Get new choke nozzles while you're at it, if it comes to that.

That's an interesting suggestion kmack. I may try it.

You also mentioned replacing the choke nozzles. I've not heard of that part before. Where is it and what does it look like?

Thanks,

Daniel

The choke nozzle is the actual piece that the needle slides into in the body of the carb. It sticks out from the bottom and is what the fuel line coming from the float bowl attaches to.

I suggest replacing it only because it might be worn a little and could let extra fuel pass that richen your mixture and give you false readings when you try to tune the carbs.

I replaced my needles and choke nozzles on my car with ones from Z Therapy. Needles and choke nozzles were $15/ea as I recall, with a $15 core charge on the nozzles. (They rebuild them)

Ya know, if you want a little more of a hot-rod needle for some more performance and you don't have to worry about smog. . . then talk to Steve at Z Therapy. Tell him your set up and he might have a suggestion to step it up a little. I know they are available. The set of SU carbs that are in UPS to me now have enlarged nozzles and needles to match among a few other mods.

Otherwise just order some replacement needles, so you know they are true.

J.M. 2 cents.

good luck

So last night I cleaned all the pieces up and reassembled. T tried to spin the needle in a drill and straighten it, but I don't think I made much of a difference. I did get it a bit straighter by pressing it on the wood bench with my hands (didn't want to use any tools and risk scratching it.)

Interestingly there doesn't appear to be any sticking at all. I really think the needle was bent when I pulled it out and has been that way for some time. I guess I'll see how it works when I get the rest of the engine together and fire it up.