Yamaha YFM35FGIW Grizzly 350 4WD 2007 Factory Service Manual (P/N LIT-11616-20–46)

• Official Yamaha Factory Publication: Yamaha Service Manual LIT-11616-20-46 (cover code 4S2-F8197-10), First Edition, November 2006. Covers the 2007 YFM35FGIW Grizzly 350 4WD IRS; Yamaha identifies model codes 4S21 and 4S25. The publication does not state a separate VIN or serial-number range.
• Factory Repair Layout: This 374-page PDF uses exploded diagrams at removal and disassembly sections, paired with numbered job/part charts, torque callouts, wear limits, special-tool references, cable-routing views, system circuit diagrams, and the YFM35FGIW 2007 wiring diagram.

Technical Specs & Configuration

The YFM35FGIW uses a 348cc forward-inclined single-cylinder, air-cooled four-stroke SOHC engine with an 83.0 × 64.5 mm bore and stroke and a 9.2:1 compression ratio. Standard compression pressure is 1,050 kPa (149 psi) at 750 r/min; the compression-test procedure also gives a 910 kPa minimum and 1,180 kPa maximum. Cold valve clearance is 0.06–0.10 mm intake and 0.16–0.20 mm exhaust. Carburetion is handled by a Mikuni BSR33, with factory data for jetting, 13.0 mm float height, 3.0–4.0 mm fuel level, and 1,450–1,550 r/min idle speed.

The drive system is covered by its actual assemblies rather than a generic “CVT” description: wet centrifugal automatic clutch, primary and secondary sheaves, V-belt automatic transmission, shaft-drive secondary reduction, sub-transmission, reverse gear, middle gear, front differential, and rear final drive. Clutch-in speed is 1,950–2,350 r/min and clutch-stall speed is 3,350–3,850 r/min. Factory backlash values are 0.10–0.30 mm for the middle gear, 0.10–0.20 mm for the final gear, and 0.05–0.25 mm for the differential gear.

The chassis uses double-wishbone suspension front and rear with 160 mm front and 180 mm rear wheel travel. One configuration detail matters during service: the rear brake is a sealed wet multiple-disc assembly inside the final gear case, and Yamaha specifies Friction Modified Shaft Drive Gear Oil, P/N ACC-SHAFT-LU-00, for that case. Final-gear oil quantity is 0.50 L for a periodic change and 0.53 L total; differential capacity is 0.23 L for a change and 0.25 L total. Engine oil is 2.2 L for a normal change, 2.3 L with filter replacement, and 3.1 L total.

Factory Repair, Setup & Diagnostic Coverage

The repair sections go well beyond periodic maintenance. They cover engine removal, cylinder-head and valve-train repair, valve-guide replacement and reaming, piston/cylinder inspection, crankcase separation, crankshaft removal and installation, transmission service, primary/secondary sheave and centrifugal-clutch repair, middle-gear service, front CV joints and differential, rear CV joints and final drive, wet rear-brake overhaul, front master-cylinder/caliper work, steering stem and tie-rod service, carburetor fuel-level adjustment, and hydraulic brake bleeding.

Gear work includes middle drive/driven gear shim selection, middle-gear backlash measurement, final-drive pinion and ring-gear positioning, ring-gear thrust-clearance measurement with Plastigauge, and final/differential gear-lash adjustment. Those procedures are backed by dedicated tool callouts such as crankcase separator 90890-01135 / YU-01135-B, gear-lash measurement tool 90890-01467 / YM-01467, sheave spring compressor 90890-04134 / YM-04134, compression gauge 90890-03081 / YU-33223, and pocket tester 90890-03112 / YU-03112-C.

Electrical diagnosis covers the DC-CDI ignition, electric starting, AC-magneto charging, lighting, signaling, oil-cooler fan control, and the On-Command 2WD/4WD selecting and differential-lock system. The manual gives component-level resistance and voltage checks and fault trees for relays, switches, the differential gear motor, pickup/stator assembly, starter system, and charging components. Representative named visuals include Cable Routing, Cylinder Head Tightening Sequence, Ignition System Circuit Diagram, Charging System Circuit Diagram, 2WD/4WD Selecting System Circuit Diagram, and the YFM35FGIW 2007 Wiring Diagram.

The maintenance charts are indexed by months, distance, and operating hours, including an initial 20-hour interval and item-specific 80-, 160-, and 320-hour intervals. The air-filter element is called out for service every 20–40 hours, more often in wet or dusty use. Hydraulic-brake notes specify brake-fluid changes and replacement of master-cylinder/caliper internal components every two years, with brake hoses replaced every four years.

Cylinder-head repair data corrects an easy point to oversimplify: the tightening diagram is a six-position sequence. Four M10 head bolts are specified at 32 Nm (23 ft-lb) and two M8 bolts at 20 Nm (14 ft-lb), with the head fasteners tightened in the prescribed sequence and stages.

Several factory cautions are especially useful during deeper repair work. The middle driven-shaft bearing retainer uses left-hand threads; treating it as a conventional right-hand thread can damage the threads. During final-gear lash measurement, the ring-gear fixing bolt is only finger-tightened—the manual warns that overtightening can damage the ring gear. When removing the middle driven pinion gear with a press, pressure must not be applied directly to the gear end because the pinion threads can be damaged.

Chapter 9 adds fault-finding for hard starting, idle and high-speed performance, drivetrain noise, shifting and clutch faults, overheating, braking, handling, and lighting. Yamaha explicitly notes that this troubleshooting section does not cover every possible cause, so it points the technician back to the related inspection, adjustment, and repair procedures elsewhere in the manual.

Safety Note: All specifications listed on this page are examples to demonstrate the manual's depth. Always rely on the complete OEM document and follow proper safety protocols before performing any hands-on mechanical work.