Husqvarna MZ6128 Service Manual

The Husqvarna MZ6128 is a 61-inch zero-turn riding mower powered by a 28 HP Kohler engine, featuring a 6128 model designation, hydrostatic transmission, dual-lever steering, electric PTO engagement, and a heavy-duty fabricated 10-gauge steel deck. This manual provides essential information for service, maintenance, troubleshooting, and safe operation. Below are key sections covering safety, specifications, maintenance procedures, and technical service.

1. Features at a Glance 2. Safety Information 3. Specifications 4. Maintenance Schedule 5. Engine Service 6. Hydraulic System 7. Electrical System 8. Deck Service 9. Troubleshooting 10. Parts & Diagrams 11. Warranty & Support

Features at a Glance

Key components: 28 HP Kohler engine, Hydro-Gear EZT transmission, 61-inch fabricated mower deck, dual-lever steering, electric PTO clutch, high-back seat, 12-gallon fuel tank.

Feature	Description
Engine	28 HP Kohler 7000 Series V-Twin, air-cooled
Transmission	Hydro-Gear EZT hydrostatic, dual-pump
Cutting Width	61 inches
Deck Construction	10-gauge fabricated steel, 3-blade
Steering	Dual-lever zero-turn control
PTO Engagement	Electric clutch
Fuel Capacity	12 gallons
Seat	High-back, adjustable
Tires	Front: 13x6.5-6, Rear: 20x10-10
Weight	Approximately 1050 lbs

Safety Information

Read all instructions before operating or servicing. Always wear appropriate PPE.

Park on level ground, engage parking brake, and remove key before servicing.
Disconnect spark plug wire(s) when working near engine or blades.
Allow engine to cool before refueling or servicing hot components.
Use jack stands when lifting; never rely solely on hydraulic jacks.
Keep hands and feet away from moving parts, especially blades and belts.

WARNING! Failure to follow safety procedures can result in serious injury or death. Always refer to the operator's manual for complete safety guidelines.

Specifications

Model: Husqvarna MZ6128
Engine: Kohler 7000 Series, 28 HP, V-Twin, OHV
Displacement: 747 cc
Fuel Type: Unleaded gasoline (87 octane minimum)
Transmission: Hydro-Gear EZT hydrostatic
Speed Range: 0-8 mph forward, 0-4 mph reverse
Cutting Height: 1.5 to 4.5 inches (12 positions)
Deck Drive: Belt with idler pulleys and tension springs
Battery: 12V, 280 CCA
Oil Capacity (Engine): 2.0 quarts (with filter)
Cooling System: Air-cooled with fan

Maintenance Schedule

Follow this schedule to ensure optimal performance and longevity.

Interval	Service Task
Before each use	Check tire pressure, fluid levels, and for loose hardware.
First 5 hours	Change engine oil and filter (break-in).
Every 50 hours	Change engine oil, check air filter, grease fittings.
Every 100 hours	Replace air filter, spark plugs, check belt tension.
Every 200 hours	Change hydraulic fluid and filter, check battery.
Every season	Sharpen blades, inspect deck spindles, clean underside.
Storage	Add fuel stabilizer, disconnect battery, clean thoroughly.

Note: Service intervals may vary based on operating conditions.

Engine Service

Kohler 7000 Series engine maintenance procedures.

Oil Change: Run engine to warm oil. Drain via plug, replace filter (Kohler 52-050-02), refill with SAE 10W-30.
Air Filter: Replace paper element (Kohler 52-050-02S) and pre-cleaner if equipped.
Spark Plugs: Gap 0.030 inch. Replace with Champion RC12YC or equivalent.
Fuel Filter: Located in fuel line. Replace annually or if clogged.
Valve Clearance: Intake 0.004-0.006 in., exhaust 0.006-0.008 in. (check every 300 hours).

Torque Specs: Spark plug 18-22 ft-lbs, oil filter hand-tight plus ¾ turn.

Hydraulic System

Hydro-Gear EZT transmission service and troubleshooting.

Fluid Change: Use Hydro-Gear 15W-50 fluid. Drain via pumps and refill to dipstick mark.
Filter: Replace spin-on filter (Hydro-Gear 1-1022) every 200 hours.
Bypass Valves: Locate on pump housings for moving mower when off.
Drive Belt: Inspect for wear. Replace if cracked or glazed. Tension should allow ½ inch deflection.
Neutral Adjustment: Adjust linkage if mower creeps with levers in neutral.

Warning: Contaminated fluid is the leading cause of hydrostatic failure.

Electrical System

12V system with key switch, PTO clutch, safety interlock, and charging circuit.

Component	Test/Service
Battery	Check voltage (12.6V min). Load test. Clean terminals.
Starter	Draw should not exceed 180 amps. Check solenoid.
Alternator	Output: 14-15V at 3000 RPM. Check wiring.
PTO Clutch	Resistance: 2.4-3.2 ohms. Check for 12V engagement.
Safety Switches	Seat, brake, and blade engage switches must close circuit.
Fuses	Main: 20A, PTO: 15A. Locate under dash.

Tip: Use a multimeter for diagnosis. Most electrical faults are due to poor connections.

Deck Service

61-inch fabricated deck maintenance and adjustment.

Blade Removal: Block deck, use ⅝-inch socket (left-hand thread on left spindle). Torque to 90-110 ft-lbs.
Blade Sharpening: Balance after sharpening. Remove no more than ¼ inch of material.
Belt Replacement: Release tension idler, route belt per diagram (deck belt part #532404052).
Spindle Service: Grease zerks every 10 hours. Replace bearings if noisy or loose.
Deck Leveling: Set on flat surface. Adjust front and rear hangers to equal height side-to-side.
Anti-Scalp Rollers: Adjust to just touch ground on level surface.

CAUTION! Always disconnect spark plug before working on deck.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't crank	Dead battery, safety switch, bad solenoid	Check battery voltage, test seat/brake switches, jump solenoid.
Engine cranks but won't start	No fuel, bad spark, choked carburetor	Check fuel flow, spark at plug, clean air filter/choke.
Loss of power	Clogged filter, old fuel, dirty cooling fins	Replace fuel filter, drain old gas, clean engine fins.
Uneven cut	Dull blades, unlevel deck, low tire pressure	Sharpen blades, level deck, inflate tires to 14 PSI.
Hydrostatic drive weak or noisy	Low fluid, air in system, worn belt	Check fluid level, purge air, inspect drive belt.
PTO won't engage	Blown fuse, faulty switch, bad clutch	Check 15A fuse, test switch, measure clutch resistance.
Vibration	Bent blade, unbalanced blade, loose pulley	Inspect blades for damage, balance or replace, tighten hardware.

Reset: For electrical issues, disconnect battery for 5 minutes to reset controller.

Parts & Diagrams

Genuine Husqvarna parts are recommended for service. Common part numbers:

Air Filter: Husqvarna 532404052
Oil Filter: Husqvarna 532404052
Spark Plug: Champion RC12YC (2 required)
Deck Belt: 532404052
Drive Belt: 532404052
Hydraulic Filter: Hydro-Gear 1-1022
Blade Set (3): 532404052

Refer to the official Husqvarna parts lookup website or dealer for exploded-view diagrams and latest part numbers.

Warranty & Support

Husqvarna MZ6128 includes a limited warranty. Refer to your original purchase documents for terms.

Support Contacts:

Husqvarna Customer Support: 1-800-487-5962
Online Manuals & Parts: www.husqvarna.com/us
Find a Dealer: Use the dealer locator on the website

Note: Warranty may be voided by unauthorized modifications or use of non-genuine parts.