Shimming needles

[81xsproject]

I was thinking of shimming my jet needles and was curious if anyone could tell me what the distance is beween the notches on adjustable needles?

[TopCatGr58]

Giving you some space.......measurements!

Hey Jessie,

I had to take one apart, get out the micrometer before I could get the measurements for you! I thought I remember seeing someone posting a message about how thick the washer that someone should use for the 80-81 series that are NOT otherwise adjustable, but I didn't try to find that!?

There is a small washer UNDER the "C" clip, and that washer looks to be the same thickness as the amount of material inbetween each notch position.

It mic'd out to be to 0.0215" thick.

The notch "C" clip was 0.016" thick....the thing that holds the needle in it's position.

To the best of my ability, the distance between the outer shoulder of 2 spaces on both sides of a notch was about 0.060".

Take that and subtract the 0.016" C-clip thickness, leaves you with 0.044", divided by 2 = 0.022"...very close indeed to the 0.0215" thickness of the washer, so that's why I'm pretty sure of that value, appx. 0.022", which is about 0.56mm.

You might try doing a search for the post about the size of the washer to use for the 80-81 carbs?!
Hope this helps!
T.C.

[81xsproject]

I did a search before I bothered everyone and only found one thread where somebody was using shims and stated a size, bit it didn't say or sound like the shims were any specifice size related to the notches. thanXS for going out and tearing stuff apart just to get me the answer. That is why you're the best. TC!!

[wingnut]

81 needle shims

I saved the following from a post a while back. Don't remember who wrote it.

"It doesn't make any difference what jets you use as long as you have the correct size.The dyno jet and K&N kits use jets based on hole size diameter and oem jets are based on flow which is more precise but much more expensive to manufacture.The jet kits give you a drill bit to enlarge the vacum hole in the slides which causes the slides to open quicker and utilize their special needles in the kit.They also give you a 190 pilot air jet to replace the stock one which in the case of an 81 Special is 185.Going bigger on the pilot air jet leans the pilot jet mixture and going smaller on the pilot air jet richens it.The kits come with complete instructions.You can use oem jets,shim the stock needles with .025 thick washers and drill the vacum slide holes two drill sizes larger depending on your altitude and get better results for less money.Generally,motorcycles from the 80 era had main jets that were close but were very lean at idle and in the lower midrange.A box stock 80-81 Eleven Special will respond nicely to simply raising the needles .025,turning the idle screws out 2.5 turns from fully seated and leaving the stock mains at 110.There again,the Standards were jetted differently. The instructions contained in the kit I got from Dennis Kirk were the same set up for all applications (altitude) and XS models including the XJ and the XJ is a completely different animal from the XS jetting wise because it uses YICS, with special instructions stating if it doesn't work call Dyno Jet.Dennis Kirk has several of these kits and is dying to sell em at $120.00 per, so call him right away.Yes,we all know there is more than one way to skin a Kaw.I hope Cody doesn't read this,he will come to St.Louis and beat me senseless"

Hope it helps

[TopCatGr58]

Hey Wingnut,

Thanks, looks I was pretty close! See bold text!
T.C.

[81xsproject]

Okay, so after my trip out to town, my question is WHERE can these shims be purchased?

[wingnut]

I haven't done it yet but here is my plan. I'm going to remove the slides from the 81 and remove the needles which sit inside the slide . See what size I need OD and ID wise and then head off to the Fasenall store with a set of calpers in my hands. They have a pretty good selection or can order some from the catalog. Failing to find something premade I my have to lap some washers on a flat plate with 400 embry paper to get the .025 I want. I'm thinking thin aluminum washers to keep the weight down. Anything heavy would be like putting in a stronger spring.

[Ken Talbot]

Evenif you find something that's close, you can open up the hole with a dremel tool or a drill bit. If the OD is too big, you can mount it on a small mandrel in a dremel tool or drill press, and file it to the size you need.

[81xsproject]

Well, I found a way to get them. There is already a washer that is supposed to be there and is just the right size (like TC said). They were available for $0.49 ea. at Bikebandit. I got 8 and shipping was $4 (yeah, right!). So, in the end they cost me a buck-a-pop.