just a touch of carb genious needed

[068ball]

just like everyone else..... can't seem to pull a straight answer from other posts and other websites on what adjustments to make. just need to get close. 77 750k, stock motor, 4-1 with shorty can, pod filters. so far I've decided to try 120 mains, 1 1/2 turns on a/f screws. what about idle jets? wanted to try changing needle clip position cuz I heard middle position is where it's at, but how the heck do I get at the needle clip on these stupid carbs!!!???......... stupid, expensive, addictive hobby.... would greatly appreciate any and all help.

 

[Stabler]

1977 would suggest PD42 carbs if they haven't been changed out.

With pods I run (on the PD42 carbs) 125 mains, .42 slow and about 1 3/4 on the a/f screw. And I use three washers on each needle wich would roughly be the "richest" position if you had different clip positions available on your needles. Which you don't. If you run the PD42 carbs that is. Mine runs great mid to high, but could probably use the .45 to help out with the idle. But the acc pump compensates so I don't notice that when pulling off the line..

I've got some pictures of how to get the throttles and needles out of your carbs here on this board, in my build thread, if memory serves. Search for Amen Savior andit will turn up.

If you need more pictures than that, let me know and I'll see what I can dig up.

 

[068ball]

is a pd42 carb the stock carb? thanks stabler for the help and I do need a high five in the face with a chair... how bout a lazy boy?

 

[Stabler]

Heh.. The PD42 carbs came stock mounted on the 77-78 models. Looking from the top on your carbs, do they look like "keyholes" or just round? The top of the carb that is?

 

[068ball]

keyholes like the one in your picture on one of your forums all tore apart.

 

[Stabler]

Allright. That picture shows where to get at the needles. From the top of the carbs.
Once you get the slides out and unscrew the 2 screws inside each slide, you'll be able to pull the needles out. Be aware, there's a tiny spring inside each slide that keeps the needle firmly in place. Don't let these shoot of. For some reason those springs color turn concrete the second they hit the floor...

If you have the stock needles in, you wont be able to change the clip position since there's only one slot/groove in each needle.
Either you get some new needles with slots/grooves, or you simply get some small washers from the hardware store to put on each needle, below it's clip, to raise each needle.

I hope this makes sence to you. I'm Swedish so I'm translating this in my head as I write..

I would say 3 washers is required on each needle (depending on washer thickness that is) but the only way to really know is to do plug chops. That's what I had to do. Look for that golden/tan look on the plugs on each throttle position.

Let me know if anything is unclear. Then I'll try and explain further.

 

[068ball]

you rock stabler!!! thanks for the help. I've gotten sidetracked on other more fun issues on this bike, carbs are no fun, what you have said makes sense to me for the most part. if I get stuck again I'll keep asking. this website is a way better source of knowledge than any service manual I have.