Snowmobile World banner

1 - 10 of 10 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
my friends have told me that i will get better performance if i jet? what is jetting and how do i do it? is it hard or can i do it by mysef? i like to do things on my own so ...

thanks

mike
 

·
Registered
Joined
·
1,643 Posts
Its an easy enough procedure but you have to know for what temps your jetting for. There should be a plug (that unscews) on the bottom of your float bowl that you remove, then with your jetting tool you can remove the existing jet and then put in the new one. I beleive the higher the number of jet the richer it will get, this would be for when it gets colder, and the lower the number the leaner it will get, this is when it gets warmer. Temp and altitude are what dictates what jet size you want. I'm not 100% sure what you should do when altitude are involved.
I almost forgot, there should be a jetting chart on your clutch cover that tells you what jets to run at what temps and what altitude.
 

·
Registered
Joined
·
277 Posts
What sled are you riding, jetting down too much can burn a hole straight through you piston, arctic cat jetting is close from the factory, be careful, if you do jet smaller on the main jets use premium fuel. :(
 

·
Registered
Joined
·
277 Posts
One more thing whenever you change jets allways use genuine mikuni jets, the aftermarket jets are all over the place in accual size I'm a toolmaker and have checked them (assuming you are using a mikuni carb). !!!
 

·
Registered
Joined
·
1,960 Posts
Originally posted by zeng62@Dec 11 2002, 03:22 AM
What sled are you riding, jetting down too much can burn a hole straight through you piston, arctic cat jetting is close from the factory, be careful, if you do jet smaller on the main jets use premium fuel. :(
I have to disagree with you on this. My 800 and others have been know to be at min, 2 sizes off. Stock is 430 mains. People have been known to go as low as 380s in the 800's. Also. I really don't see why you would ever have to run premium with rejetting. Makes no sense. Your not changing compression or anything. Don't want to start a war here but lets not give Mike any incorrect info. I have come to know and trust a lot of people on this site. Let's keep it that way. :thumbsup:
 

·
Registered
Joined
·
3,008 Posts
sledneck,
I'm with rf on this one, Cats tend to be jetted at least two sizes rich from the factory and NO you don't need to use premium fuel if you jet down.
The best idea would be to post what model, year and engine size sled your riding along with where (elevation) you mostly ride. I would bet several folks with the same sled will be able to advise you on what's safe jetting wise for your sled.
As for the advise on buying jets always buy genuine parts from the mfg of whatever carbs are on your sled. Aftermarket jets can be too big and or too small by several sizes leaving you with either a very poor running sled or a smoked one.
With care and research you will be pleased with the results.
Rick.
 

·
Registered
Joined
·
3,910 Posts
I would run premium but its not nessessarry.

When ever you get a engine to make more power and run hotter it is safer to run 91 or above octane. 91 burns cooler and slower then 87 and will save your sled if temps go up outside.

And I would only run 91 for lakes.
 

·
Registered
Joined
·
80 Posts
Where do you jet the replacement jets?
Thanks, SWRules

Joe
 

·
Registered
Joined
·
1,960 Posts
Either your dealer or at any of the shops by your house. As long as they have the ones you need that are OE
 

·
Registered
Joined
·
2,422 Posts
Sledneck, messing with jetting can cause you [yourself] to blow a gasket when a big round hole is in the middle of your piston!
Get a book on jetting or learn from someone that is experienced at it.
Jetting down can be good if you know what your doing.
Examples; reading piston wash, plug color & electrode readings.
Even a set of EGT gauges is useless without reading the above to get a baseline accesment.
As far as jets, Mikuni jets are the only way to go, as Zeng62 said, aftermarket jets ARE way off in either directions. Genuine Mikuni jets are always marked on top, not the sides.
Premium fuel is good insurance for keeping a burndown away. Most people think premium fuel will make you go faster,WRONG! It just burns slower and cooler where junk 87 octane is very hot burning.
If you want to run your sled on the edge then you better run premium fuel, if you dont want to re-jet for temp changes, you better run premium. Even running on the edge with premium in zero weather is no guarntee that you wont burn down.
Play it safe and run a little fat, your wallet will love you!
 
1 - 10 of 10 Posts
Top