TOPIC:

scotch wrote: A '79 came with a needle with only 1 groove. '80 & on had five so there is the obvious ability to play with the top end mixture to a degree. With a DG header I 'm running on the factory #3 slot. Definitely TOO LEAN dropping the needle down one (raising the clip by one) so put it back to #3.. There's other details that could be fattening the top end but if you're going to have the carbs out to check the needle positions then you'll address. Float levels, O-rings and air supply passages at that time.

Okay thanks - so basically there is no needle adjustment with the carbs on my 79 ... is it possible to just get needles from the later models that can be adjusted via clip position, and put those in my carbs?

<....is it possible to just get needles from the later models that can be adjusted via clip position, and put those in my carbs? ....>

Yes. Some of the aftermarket carb rebuild kits have the 5-slot needles. I have no experience with these kits. Jets, emulsion-tubes needles, float-valves assemblies, bowl-gaskets and O-rings are usually included but take note: As told by some - the aftermarket spring-clip used to retain the float-valve needle can cause the needle to hang-up. Use your OEMs' !
Anyone undertaking any work on the carbs should have three dedicated flat screw-drivers to remove the High-speed jet, the Idle-jet and Idle-jet tower cap. Grind/file them to fit the slots fully ( no slop) and in the case of the Idle-jet - slightly narrower so the edges don't touch the internal threads inside of the Idle-jet tower. I'm referring to the blade width - not the thickness
More people have F*&%'D up jets and caps by using what ever size flat driver they thought they could manage with. Specifically In the case of the Idle-jet all you have to do is use a sloppy fitting driver, burr the top of the jet and/or the towers internal threads and you're, screwed - no pun intended!

scotch wrote: <....is it possible to just get needles from the later models that can be adjusted via clip position, and put those in my carbs? ....>

Yes. Some of the aftermarket carb rebuild kits have the 5-slot needles. I have no experience with these kits. Jets, emulsion-tubes needles, float-valves assemblies, bowl-gaskets and O-rings are usually included but take note: As told by some - the aftermarket spring-clip used to retain the float-valve needle can cause the needle to hang-up. Use your OEMs' !
Anyone undertaking any work on the carbs should have three dedicated flat screw-drivers to remove the High-speed jet, the Idle-jet and Idle-jet tower cap. Grind/file them to fit the slots fully ( no slop) and in the case of the Idle-jet - slightly narrower so the edges don't touch the internal threads inside of the Idle-jet tower. I'm referring to the blade width - not the thickness
More people have F*&%'D up jets and caps by using what ever size flat driver they thought they could manage with. Specifically In the case of the Idle-jet all you have to do is use a sloppy fitting driver, burr the top of the jet and/or the towers internal threads and you're, screwed - no pun intended!

I'll second the motion to grind up a set of screwdrivers just for removing installing the jets. I took Scotch's advice and did this. Sure beats munching up a set of jets or mutilating the threads in the carb bodies.

Sage advice - thanks guys. I do have a bench grinder and should have a few extra flathead drivers laying around - when I get to that point I will make sure and carve some up ...

Hello srech77. Firstly, a warm welcome from me! I have been following your posts and all the good advice given to you by a few of our very knowledgeable members.....thanks gents....these discussions are always good reading and enlightening! Talking about the carb kits, should you purchase aftermarket carb kits, like Scotch mentioned, use your original float needle retaining clips.....but also check that the little 'O' rings that come for the airscrews are not undersized! I had this issue a few weeks ago and couldn't get my mixtures right......only to find that the 'O' Rings were undersized and not sealing in the carb bodies!

srech77 wrote: Sage advice - thanks guys. I do have a bench grinder and should have a few extra flathead drivers laying around - when I get to that point I will make sure and carve some up ...

I have a flat blade screwdriver purchased specifically for the job. It has straight sides that just fit through the threads above the jets. It has a quality precision ground blade that fits snugly in the slot in the brass jet. The screw driver always goes back to the plastic retail hanger that it was purchased in - and NEVER gets used for anything else!

The jets are a real SOB to get out once someone has caused them to burr out - which is all too easy