What kind of main jets have you guys found best for your 99 or 2000 MachZ's? I'am talking stock or slightly modified good for -20.
Both 99 and 00 stock run all three jets the same where on the older Z's usually the center cyl. was fatter. How much to fat if any is the jetting?
I know I know, plug color and piston wash but what are your experiences... :doh:

'98 Mach Z with v-force 2 and center dump pipes , the rest was stock.

300/310/300 main
lowered jet needle one step ( leaner )

no prob so far ....

i ride at sea-level in quebec.

Same sled, same set up, but gutted box, 290/300/290 edgy at 1000' at o*, sure it would melt at -20 or at 1500' at zero

Wow KawaBoga, you droped 3 sizes! What temp is that safe for?
Were talki'n center dump pipes for the 98's but 99 up had end dumps.
01 and 02 Mach's run 290 mains with everything else in the carb identical. I E-mailed Skidoo on this but they couldn't give me a straight answer. The air box even looks the same from the outside.
End dumps on the old F- chassi's were, without looking, I think up in the 400's if this means anything.

Every motor is a little different. I run EGT's and can tell you a stock '97, the 380,380,380 (if I remember right), main jetting was pretty good, I run egts and you could go down to 370's, but if it was real cold this may smoke something down a long pull. My 99 z runs 280,280,280, but I think a long pull around 0 to -5 might smoke something. I've also dropped the needle, and put 45 pilots in the 99. The 99 has a head cut/base gasket mod, and boyesen reeds. If it gets real cold and I'm riding, I put powerjets on the carbs(for a turbo couple of years back, which is off now) so I can turn the jetting back up if I want. the 99 also has coated pistons, which make a difference as well. I like the vari-flow much better than the powerjets, as I'm running during the day I can just Dial-up my jetting without even stopping the sled. But again, without EGT's you should alway stay on the rich side unless you want to be worried every time the temp drops, not to mention barometric pressure.

I'am putting on a Dynoport can soon and from the story from Rich Daly of Dynoport, a dyno was done on a 98 Mach with V-force reeds and the can and Rich said they could had leaned down 1 with this set up. I have also heard from some that V-Force tends to make it run a little rich also.
My 2000 is set up exactally like this, this is why I feel I could go down from 310 to 290, let alone if it were stock I could prpbably drop 1 for sure.
What ever I do I think I will leave the center cyl. 1 rich, as I have a thermostat now where 97-98 was the only year the 809 had one.
More info. please! ;)

I didnt drop 3 size , jetting was 330/340/330 from factory .... was running way too fat so skidoo made a recall to set the jetting to 310/320/310. I dropped only one more size on main and dropped jet needle because i installed V-force II.

I checked my plugs a few times on cold day and they were light coffee brown.

This year with CrankShop pipes , thicker base gasket / head mods ... i'm going to start with 350/360/350 main jet , put my jet needle back to stock. I don't know if this jetting is correct but i want to stay on the safe side with all the mods going at once.

Thats a real good place to start, beore you drop, happy tuning.

Just came back from a 100 miles ride with my sled with above modifications.

Elevation was 2400 f , temp about 40 f

I don't know what exactly is going on ...

- Have to push trottle HALF WAY to rev up to 7000 and i was barely hitting 60 mph ...
- Max rpm was 7700-7800 ( should be 8600 )
- Big lack of power !! ??? ( maybe 80 hp ? ) (should be about 160)
- Top speed about 75 mph
- 6.5 miles per gallon or 60 miles per tank ... OUTCH
- Intermittent response from engine
- MAG cylinder plug was sooty and black.
- MAG Cylinder/pipes soaked with fuel/oil ?
- Exhaust gases are visible and blue ?
- PTO and center dark brown electrode but the side is black.
- I have fire on all 3 cylinders but MAG is darker

Anyone have suggestions on what to check ?
I know im probably too rich because i got 60 miles with a full tank of gaz :cussing: but do you think this could be something else ?

stock pipes jetting was
300/310/300

jetting with crankshop pipes this weekend was
350/360/350
+1 jet needle.

If it's only jetting , what do you think about 320/330/320 and back to stock jet needle position ?

Any suggestions will be appreciated

Didn't Crankshop give you any kind of jetting changes in the instructions?
In stock form you are jetted for about -70
You are getting into some serious changes and a set of EGT gauges would be in order. Ya, I know there 3-$400 bucks but if you want'a play you gotta pay.
Now like me here I'am to cheap to by them but mine is stock and I'am looking for an easy way out. I could test and test but I was hoping someone else as already been down that road.

KawaBoga, it sounds like you have a problem with the mag carb, maybe a leaking needle & seat or a stuck float i have even seen the main fall out needle jet it was laying in the bottom of the bowl.

Drop 4 jets and hit it for 500', christ it was 40' out, the starting spot we speculated at was for -20, that alone is 3 jet sizes, and that still was probably rich.

hey kawaboga when was the last time you cleaned your carbs? I had a similiar problem with my mach1 i had bad gas mileage and barely could hit 60 ended up needing to go thru the carbs and clean them good might want to give that a try.

Kawaboga,

It's probably a richness problem, but somehow the symptoms seem more like a timing issue.

You probably had to re-time your sled after you installed the pipes - right?

your problems resembles a spark timing that is way too retarded.

was up in munising last season rode over to christmas power sports talked to scott the service manager. i could'nt get over 70mph he asked if i gapped the plugs to spec. did this and it ran like it should he said doo's dont like to run unless there to spec's it work for me. i ride a mach millennium???

If it was a timing issue all three spark plugs would be the same.

Yeah mr670, your probably right. Although I have seen people adjust thier oun timing and get it messed up before, just something to check.

i just bought a 97' mach z and the center jet is 1 size smaller than th mag and pto jets, does this sound right?

Maybe you have a stuck choke .... I have a Mach-z it's a 96 780 jetting is 370 380 370 .... was only getting 7.5 mpg .... till I found out the choke was stuck ....

I know my timing is stock ...

The sled started to pull real hard 10 sec. before i ran out of gaz...

I don't have any spec from crankshop, the pipes are used. I will call today.

I got my dealer to check it. I will post when i have news.

This is easy, the sled is so rich taht your dropping one cylinder and the other two are too rich also. The jets you said you have in it are just too big. You have one of two choices, either drop two or three jet sizes or pour in 8 oz of Extreme Power fuel additive per gallon of gas. That will help wake it up! Either way it is way too rich! Good Luck.

I just came back from my dealer , the jet needle is now back to stock position , main jet is 330/340/330

Now plug are light brown ... motor is pulling real hard if the air filter is remove

The engine run 9000 rpm if we remove air filter from the airbox but A LOT less with a new air filter on...

like 1000 rpm less or more ... he is going to try with another air box tommorow from a mach z 2000 to see if it fix my problem.

was the air box ... too much restriction for some reason....

same thing happened with my 98 mach1 had problems with it gonig over 60 mph would run better when i took off the airbox ended up the carbs were dirty had them cleaned ran great after that