Fuel System/Carburetion - 1998 Specifications; 1998 Trail Boss W98Aa25C (Engine -Ec-25Pfe-10) - Specifications And Clutching And Jetting Guidelines For Altitude And Temperature - Polaris Magnum 2x4 Service Manual

FUEL SYSTEM/CARBURETION
1998 Specifications
1998 TRAIL BOSS
W98AA25C
(Engine - EC-25PFE-10)
SPECIFICATIONS AND CLUTCHING AND JETTING GUIDELINES
FOR ALTITUDE AND TEMPERATURE
Carburetor, Mikuni VM30SS
Main Jet - 145 Pilot Jet - 40 Float Level - Float arm parallel with bowl gasket surtace (Page 4.22)
Jet Needle - 5DP7-3 Needle Jet - 0-4 (169)
Air Screw - 1 Turn Cutaway - 2.0 Needle Seat 2.5
Flywheel Marking: FF45 COl Marking: CU2167 Alternator Output: 150 Watts
Ignition Timing: 25° BTDC
@
3000 RPM (± 3°) Spark Plug: BR8ES Gap: .028 (.7mm)
Operating RPM: 6000 (± 200) Idle RPM: 700 (± 100)
Turn out (counterclockwise) one quarter turn for each 30 degrees above 60 degrees F.
Observe the following altitude recommendations and set up the vehicle accordingly.
Altitude AMBIENT Below O°F 0° to 40°F +40° to +80°F +80°F & Above
TEMPERATURE
(Below -18°C) (-18°C to +5°C) (+5°C to +26°C) (+26°C & Above)
Meters 0-900
170 155 145 135
(Feet) (0-3000)
900-1800 155
(3000-6000)
1800-2700
140
(6000-9000)
2700-3700 130
(9000-12000)
r
I -
Pilot air screw out 1/2- 3/4 turn from lightly seated
Clutching
Altitude Shift Clutch Driven
Weight Spring Helix
Meters 0-900
16
Blue/Green 2-2
(Feet) (0-3000)
900-1800 16 Blue/Green
2-1
(3000-6000)
1800-2700 16 Mod Blue/Green
2-2
(6000-9000)
2700-3700
16 Mod
Blue/Green 2-2
(9000-12000)
5/98
4.4d
Polaris Industries Inc.