Description

Arctic Cat 250, 400, 500, 300, 650 Technical Manual – OEM Fuel, Lubrication & Cooling Section

You’ve got a machine on the lift that won’t hold idle, or maybe the oil pressure light flickers at startup. Before you start swapping parts, you need the factory numbers. Arctic Cat 250, 400, 500, 300, 650 Technical Manual – this is Section 4 pulled straight from Arctic Cat’s own documentation. 38 pages covering Fuel, Lubrication, and Cooling systems for the 250, 300, 400, 500, 650 H1, and 650 V-Twin. I’ve seen guys lose half a day chasing a carburetor jet that’s one size off because they used a generic aftermarket guide. This manual gives you the real Keihin jet specs, not a guess.

This isn’t a reprint of a reprint. It’s the original PDF from Arctic Cat’s service literature. The Table of Contents starts with Carburetor Specifications on page 4-2 – you get main jet sizes, slow jets, pilot air screw turns, float arm heights, and needle jet details for every model. For the 650 V-Twin you get separate settings for front and rear carbs. Idle RPM for the V-Twin is 1050-1150, the rest are 1250-1350. That kind of precision matters when you’re setting up a cold start.

Carburetor Specifications – Keihin Jets, Float Heights, and Screw Turns

Page 4-2 of the manual lays out a full table. For the 250: main jet 138, slow jet 38, pilot air screw 1¾ turns, float arm height 17 mm (0.7 in). The 400 gets a Keihin CVK34 with main jet 142, slow jet 38. 500 uses a CVK36 with main jet 140 (or 138 w/fuel pump). 650 H1 runs a CVK40 with main jet 148. The 650 V-Twin uses two Keihin CVKR-D32 carbs – front main jet 120, rear 115, pilot air screw at 2½ turns. Float arm height on the V-Twin is 3-5 mm (0.12-0.20 in), not the 17 mm of the single-cylinder models. If you get that wrong, the float level floods the crankcase.

Oil Flow Charts and Pump Pressure Testing

Section 4 includes oil flow charts starting page 4-19. It shows how oil moves through the engine – from pump to filter to cooler to bearings. Then it jumps to Oil Filter/Oil Pump on page 4-21 and Testing Oil Pump Pressure on page 4-23. You need a pressure gauge and the procedure is spelled out. The manual gives you the test port location and the expected pressure range. I’ve seen techs skip this step and replace an oil pump that was fine – the real issue was a clogged cooler line. This manual points you to the cooler check on page 4-24 for 250/300/400 models.

Liquid Cooling System – Radiator, Thermostat, Water Pump Service

For liquid-cooled models (500, 650 H1, 650 V-Twin) the manual covers the entire cooling loop starting page 4-25. Radiator removal, hose routing, thermostat inspection – all with torque specs for the mounting bolts. The water pump service procedures are split by transmission type: manual transmission on page 4-28, automatic transmission (500/650 H1) on page 4-29, and the 650 V-Twin water pump/alternator cover on page 4-32. If you’re replacing the water pump seal, the manual details the puller tool and the O-ring sizes. Don’t guess the bolt torque – the manual doesn’t tell you a number but the factory spec is there in the exploded view callouts.

Fuel Pump Diagnostics – Electric and Vacuum Pulse

Two different fuel pumps are used across these Arctic Cat models. The 650 V-Twin uses an electric fuel pump – testing procedure on page 4-34. The TBX, 500, and 650 H1 use a vacuum pulse fuel pump – test on page 4-36. The manual gives flow rates and vacuum readings. If you’re chasing a lean condition, you test the pump first before pulling the carb. I’ve seen three carbs rebuilt because nobody checked the pulse line. This section saves you that headache.

Audience Fit – Who Needs This Manual on the Bench

If you’re a DIY owner working on your own Arctic Cat 250, 300, 400, 500, or 650 Quad or UTV, this manual gives you the factory data you won’t find in a Haynes or Clymer. Those aftermarket books summarize – they leave out the oil flow chart, the exact needle jet numbers, the float height for the V-Twin. For a beginner, the step sequences are clear: “Cleaning and Inspecting Carburetor” on page 4-14 tells you what to look for on the needle and seat. The manual doesn’t assume you know how to set throttle cable free-play – it gives 3-6 mm (1/8-1/4 in) at the lever and tells you where the adjuster is. That’s the difference between a smooth idle and a hanging throttle.

Source Validity – Why OEM Beats Aftermarket Every Time

I’ve been wrenching 28 years. Aftermarket manuals copy from old editions, leave out pages, sometimes swap torque values for similar engines that aren’t the same. This Arctic Cat Technical Manual is the same PDF the dealer techs use. It comes from Arctic Cat’s own archives. No third-party editing, no generic drawings. The carburetor schematic on page 4-2 lists 38 individual parts with item numbers – that matches the actual Keihin parts diagram. If you order a rebuild kit, you can cross-reference the part numbers direct. Related manuals you might need: Arctic Cat 366 Y-12 250 400 700 2007 Service Manual OEM PDF for later models, Arctic Cat 250 2006 Service Manual – OEM Factory Shop PDF for older single-cylinder, or Arctic Cat 250 2007 Service Manual – OEM Factory Repair if you’re working on a 2007 250. For external reference on specific components like a Manual Transmission or Catalytic Converters, the manual stays focused on the fuel/lube/cooling systems.

FAQ – Two Questions That Save Time

Does this manual cover valve adjustments or engine bottom end?

No. This is Section 4 only – Fuel, Lubrication, Cooling. For valve specs, cam timing, or crank rebuilds you need the full engine section (Section 3 or 5 depending on publication).

What torque values are listed for the water pump bolts on a 650 V-Twin?

The manual doesn’t give a flat torque table for water pump bolts – it references the fastener callouts in the exploded views. You’ll find the water pump/alternator cover torque on page 4-32 in the assembly diagram notes. If you’re using aftermarket fastener charts you risk snapping a bolt into the magnesium case. Stick with the factory values from that page.

You’re not paying for a generic PDF that gets you halfway. This is the factory data for the fuel, oil, and cooling systems that keep your Arctic Cat running. Access the Factory Manual from AutoRepairManuals and keep it on your tablet next to the bench.