i know that Dave Dodge sells the shim kits but i was wondering if i found the 3 mm washers at the home depot would these work the same way. also would i need to adjust the fuel air mixture screws also :?:
The shims that Dave has in his kit are .020" thick, you can get them at Radio Shack..
iirc they are #4 electronics washers.
Specs - 18-8 Stainless Steel MIL Spec Flat Washer #4 Sz, No. 803, .125" ID, .250" OD, .017"-.028" Thk (they mike out at appx .020")
I buy them in packs of 500. If you have a few days to wait I can mail them to you gratis. Just PM me a mailing address. If you don't want to wait they are readily available locally.
Billy were do you get them, I could use a large supply, as I burn through them quite often with all the shims installations I do..
Quote from: Greg CothernBilly were do you get them, I could use a large supply, as I burn through them quite often with all the shims installations I do..
I don't recommend the Radio Shack washers, they vary in thickness too much. If you don't need hundreds, McMaster-Carr has them. I can give you the part number, but I'll need to look it up. If you need really large quantities, I have a source that's much less expensive, and I can "piggyback" an order for you. You can call me at 972-221-8902
Quote from: Greg CothernBilly were do you get them, I could use a large supply, as I burn through them quite often with all the shims installations I do..
http://www.mcmaster.com/ Part # 98019A309 under $7.00 for a 500 pack. As far as the variance in thickness it is not a biggie. I just mike them and pick 4 that are the same within a few thou of .020" It ain't that critical no matter what some say. McMaster is a good source for metric hardware, 3 day delivery and have never screwed up an order to me although if someone has a cheaper reputable source it would be great if they posted it. :D
Billy thanks a bunch I appreciate it... I also have not had a problem with Radio Hacks washers (on Dave Dodges advice to use).
However I want to have a larger supply on hand to give out to the MOOT regions for MOOT'sters to not have to buy them..
Ok, I hope this isn't turning into an "oil thread" situation, but here goes. Needles are ground very precisely for a reason. . It's the same reason that slow jets are so precise. You definitely want to raise the needles equally, and precisely. The difference might only be a few thousandths, but you wouldn't casually substitute a 38 slow jet for a 35 slow jet.
When your setting up carburetors, working with precision should be a primary concern. "Close enough" will work, and it's easier, but it's not that difficult to get it right, not just close.
As for Dave, well, I'll be having a talk with him on this subject! :roll:
If anyone want to use nice, stainless, precision shims under their needles, let me know and I'll get a set out to you.
I just talked to Dave about this, and he stressed that late model Magna carbs are so touchy that even 1/8th turn on the pilot screws makes a big difference. He also mentioned that when he shims needles, his tolerance is around .0005 (one half thousandth) between shims.
My point was to mike them out and pick 4 of the same size. Whether they are all four .018" or .022" or somewhere in between won't make a rat's arse bit of difference that could be measured anywhere short of on a dyno with an air/fuel sniffer and even then it is doubtful. Get a speck of carbon on a valve between runs and you just threw the measurements off as much as the 2 thou needle shim will. Of course we can argue all day about it. I like being right as much as the next guy. Maybe you should share that source with Greg privately so he can take care of our fellow riders in other regions? Hmmm? I am pretty sure you can get the washers at McMaster in what is called precision shims if one feels it is that critical to have them exactly at .020" +/- 0.0005. Cost will jump to appx 24 cents each iirc.
McMaster site
Bearing Shims
Part # 93574A188
(Same as 93574A175)
18-8 SS Precision Bearing Spacing Shim .020" Thick, .123" ID, .178" OD
In stock at $7.81 per Pack
This product is sold in Packs of 25
Overkill imo but for the perfectionist there they are.
Quote from: Billy CI am pretty sure you can get the washers at McMaster in what is called precision shims if one feels it is that critical to have them exactly at .020" +/- 0.0005.
I think you might have misunderstood this point. Dave mentioned that it's best to have the individual shims measure within half a thousandth of each other, so the "lift" is equal.
While it's true that being off just a little won't make a big difference, it's also true that small differences can add up. Your shim is a little off, the floats aren't perfectly set, a small difference in a jet orifice, it all adds up. I used to race shifter karts, and once met my engine builder at his shop. You wouldn't believe the tolerances he held these engines to. When I made a comment about how these minute differences could make any real difference in the engines, I got a good 20 minutes on the subject!
I think that made me feel just a little bit better about a $3000 bill for an 80cc longblock! By the way, we were getting around 28 horsepower from something like 5 cubic inches. But I guess I'm pretty far off topic now.
hmmm each carb is slightly different cause they are not CNC made so slight variances are not going to wreck the system. This is why you sync em if you want to get them as perfect as you can, but the margin for whats in sync and what is not is quite large IMO.
So I say lets all just get out and ride and enjoy our steeds!!!!!!!!!!!
You can also get the shims here. They also sell the jets if you're so inclined.
http://www.z1enterprises.com/detail.aspx?ID=1934
I have these jets/shims in my 01 Magna, they work just fine.