Carb Specs for Ski-Doos
I have attached a file listing the carb specs for a number of years of Ski-Doos (Mikuni carbs.)
Also, you can find important information about the "Jet Needle" (which attaches to the throttle slide) at the following link to a WPS catalog page:
http://www.wps-inc.com/catalogs/snow#Task=PREV&CICID=SM&PRVCID=SM&PAGE=635&Rnd=8133555180193585
Ignore the 13- part of the part number, that is just the WPS prefix added to Mikuni numbers. The 6- needles are used in the 38 mm carbs and the 7- needles in the 40 mm carbs. (Remember, the Needle Jet is the metering orfice of the pair and the Jet Needle is the tapered needle that effectively reduces the orfice size. However, the "Needle Valve" is the part in the float bowl that permits regulates fuel entrance to keep the float bowl fuel level constant.) The Needle Jet/Jet Needle pair meters fuel at throttle openings from about 1/4 to 3/4 open.
This chart from Sudco offers more actual dimensions for Jet needles and shows how the Mikuni jet needle numbering system works.
http://www.sudco.com/vol33/56-59.pdf
You should start with the jetting listed for a non-HAC model of the same year and displacement.
As mentioned earlier, the 1997 MX Z with a 583 cc motor was non-HAC. However, it ran 40 mm carbs -- the Summit 583 ran 38 mm. So you can expect that your jetting may be just a little different.
You can also get an idea for jetting by looking at a non-HAC 583 of another year -- the 1999 Formula DLX 583 ran 38mm carbs and very close to the same jets as the '87 MX Z.
Stay on the rich side at first and read your plugs to see how lean you can go.
