Snowmobile World banner

1 - 9 of 9 Posts

·
Registered
Joined
·
354 Posts
Discussion Starter #1
What is the factory pilot jet size on this motor? Would I be asking for trouble dropping down a size knowing about the lean midrange that these motors have? I ride at 1,000 - 3,000 feet. I never have the throttle pinned for long periods. Looking for a little better off- idle response. Reeds installed. Mains 460. Otherwise stock.
 

·
Registered
Joined
·
3 Posts
800 has 17.5 pilots jet needle from a 99 600 really help wake it up 460's are a little to lean dont you think ?.was 520n's stock =560
 

·
Registered
Joined
·
400 Posts
I agree with Douglas unless you are running a different mods
to run so much leaner than stock on the main jet.

I've tried a 20 pilot and it helped a little with the mid range
lean condition, but not alot (or course its just a pilot). I
wouldn't go with a 15. Try adjusting your air screw.

Are you running EGT's? Can you read plugs or piston wash?

I know one guy who was running 470's on an 01 800 and
I thought that sled was running lean.

Changing the jet needle to an adjustable one could help you
in the midrange. A 942 needle.
 

·
Registered
Joined
·
354 Posts
Discussion Starter #4
I can read wash and plugs. Reeds called for down three on main jet plus at elevation the thing was way fat. I will probably try the air screw when temps are cooler.
 

·
Registered
Joined
·
132 Posts
this may sound stupid but i am just trying to learn these small motor so i have to ask

what do the pilots control ?

the main jets control all the way from idle to wide open (right)

have to learn somehow so i thought i would ask
 

·
Registered
Joined
·
400 Posts
Actually, the main jets control from about 1/2 throttle
to wide open.

The pilot and air screw control idle to maybe 1/4 throttle.

The jet needle and needle jet control in between.
 

·
Registered
Joined
·
354 Posts
Discussion Starter #8
Rab, when you say new do you mean 01 tm carb on my machine? If so where is this screw and will it lean out mixture through the throttle range or just off idle? I tried(briefly) to locate an online diagram of my carb but no luck. Anybody know of a good site with tuning tips added as a plus?
 

·
Registered
Joined
·
9 Posts
ya, id like to know where that fuel screw is on TM carbs too.
 
1 - 9 of 9 Posts
Top