1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 373Get this manual
ENGINESCARBURETION 1988 Trail Boss Trail Boss 4x4
Engine Model NumberEC25PF-03 Carburetor TypeVM30SS Main Jet145 Needle Jet0-4 Pilot Jet35 Jet Needle5DP7-3 Cut Away2.0 Air Screwturn
Altitude-Meters (Feet)
0-900 (0-3000) 900-1500 (3000-5000) 1500-2200 (5000-7000) 2200-3000 (7000-9000) 3000-3400 (9000-11000) -200 170 160 150 140 135 0+20 160 155 145 135 130 +20+40 155 150 140 130 125 +40+60 150 145 135 125 120 +60+80 145 135 130 120 115 +80+100 140 130 125 115 110
1988 Trail Boss 250 RES
Engine Model NumberEC25PF-04 Carburetor TypeVM38SS Main Jet230 Needle Jet0-4 Pilot Jet45 Jet Needle6DH4-3 Air Screw1.5 turn Cut Away3.0
Altitude-Meters (Feet)
0-900 (0-3000) 900-1500 (3000-5000) 1500-2200 (5000-7000) 2200-3000 (7000-9000) 3000-3400 (9000-11000)
-200 270 250 240 220 210
0+20 260 240 230 220 200
+20+40 250 240 220 210 195
+40+60 240 230 210 195 190
+60+80 230 220 210 195 180
+80+100 220 210 200 185 175
All 1989 Models
Engine Model NumberEC25PF-05 Carburetor TypeVM30SS Main Jet145 Needle Jet0-4 Pilot Jet40 Jet Needle5DP7-3 Air Screwturn Cut Away2.0