Kunz AcrEase MR55B User manual

1/18
57” ROUGH CUT
OWNER’S MANUAL
With Assembly Instructions
For Model: MR55B
KUNZ ENGINEERING, INC. / MENDOTA, IL 61342 / PH [phone]

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1
SAFETY INTRODUCTION
Your safety, and the safety of others, is very important. To help you make informed
decisions about safety, we have provided operating procedures and other information on
labels and in this manual. This information alerts you to potential hazards that could hurt
you or others.
This safety alert symbol is used to indicate safety instructions. Follow these
instructions to avoid personal injury and/or property damage. Read and follow all
instructions in this manual and the included engine manual.
You will find important safety information in a variety of forms, including:
Safety Labels – on the mower.
Safety Messages – preceded by a safety alert symbol and one of three signal
words: DANGER, WARNING, or CAUTION.
These signal words mean:
DANGER:Indicates an imminently hazardous situation that, if not avoided, will result in
death or serious injury. This signal word is to be limited to the most extreme situations
typically for machine components which, for functional purposes, cannot be guarded.
WARNING: Indicates a potentially hazardous situation that, if not avoided, could result in
death or serious injury, and includes hazards that are exposed when guards are removed.
It may also be used to alert against unsafe practices.
CAUTION:Indicates a potentially hazardous situation that, if not avoided, may result in
minor or moderate injury. It may also be used to alert against unsafe practices.
This entire manual is filled with important safety information. Please read it
carefully.

2
IMPORTANT SAFETY INFORMATION
WARNING: Do not allow anyone to operate this equipment who has not fully read and
comprehended the safety manual and who has not been properly trained in the safe
operation of the equipment.
WARNING: Operator should be familiar with all functions of the unit.
DANGER:Keep hands, feet, hair and clothing away from moving parts.
WARNING: Remove all objects from the work area that might be picked up and thrown by
the blades.
WARNING: Do not mow when children and others are around.
WARNING: Keep all safety shields and deflectors in place during operation.
WARNING: Shut off the engine and allow the mower blades to come to a complete stop
before making any adjustments to the mower.
WARNING: Shut off engine before disconnecting the mower from the tow vehicle or
attempting to move the mower by hand.
WARNING: Never carry children or passengers.
WARNING: Do not allow children to operate this machine.
WARNING: Follow all safety precautions outlined by the manufacturer of the tow vehicle
being used to pull this product.
This entire manual is filled with important safety information. Please read it
carefully.

3
SAFETY SIGNS AND LOCATIONS
Clean or Replace Any Safety Signs That Are not Readable or Damaged
Replacement decals can be purchased from your local dealer or
Kunz Engineering Inc.
Mendota, IL 61342
[phone]
275003 – Danger
Decal, Cut Hand & Foot
275007 – Warning
Decal, Belt Sheild
275002 – Warning
Decal, General
Serial # and Model #
Decal

4
ASSEMBLY INSTRUCTIONS
Read the complete assembly instructions before starting the assembly.
You should have:
- one mower deck assembly
- two carrier arm assemblies
- two rear tire assemblies
- one ATV tongue assembly
A. ASSEMBLY OF MOWER WHEELS
1. Set the mower deck assembly on wood blocks so that it is suspended off the ground.
Note: The operator controls are on the front of the deck. (Left and right are determined by
looking in the direction of travel or by standing at the rear of the deck assembly looking
forward.)
2. Install the rear tire assemblies on the carrier arm assemblies. Remove the hex nut and lock
washer from the rear tire assembly and install the 5/8”x7-1/2” tire axle bolt through the hole in
the carrier arm assembly. See figure 1. Secure assembly with the lock washer and hex nut
provided on the rear tire assembly. The rear tires should be offset to the outside of the deck
assembly on both sides. See figure 2.
3. Install the two carrier arm assemblies in the pivot arms, which are located on the mower deck
assembly. Place the assembly so that the castered tires are on the front and the fixed tires are
on the back. See figure 2. Secure with 1/2" x 3-1/2" hex head bolts and lock nuts provided on
the pivot arms. Mount the height adjust screw on the deck assembly in the hole provided.
Secure with the 1/2”x1” hex head bolt and lock nut provided on the height adjust screw.
Note: Tighten 1/2” x 3-1/2” and 1/2” x 1” hex head bolts until just snug. This area needs to
pivot when adjusting the height. Under tightening can result in excessive wear and
flexing. Over tightening will make adjusting the cutting height very difficult.
B. INSTALLATION OF TONGUE ASSEMBLY
1. The tongue can be installed either on the left or right caster assembly depending on how the
tow-behind mower will be towed. See figure 2. Secure the hitch pivot on the chosen caster
assembly with the 1/2” x 3-1/2” hex head bolt, lock washer, and nut provided.
2. Install the tongue into the hitch pivot and secure by placing the provided 5/16” wire lock pins on
each side of the hitch pivot.
Note: To help prevent any unwanted pin removal caused by oncoming debris install the 5/16”
wire lock pins with the wire lock section back from the direction of travel. See Figure 3.

5
Figure 1: Rear Tire Assembly Installation
Figure 2: Assembly of Carrier Arm Assy., Hitch Pivot, and Tongue
Flat Washer
Rear Tire
Carrier Arm
Assembly
Hex Nut and
Lock Washer
Cup Washer
Bolt
Spanner
Tube
Rear Tire Assy.
(Attach on outside for
both left and right sides)
Pivot Arm
Height Adjust
Screw
Hitch Pivot – Attach to
Either Left or Right
Carrier Arm Assy.
Tongue
Front (Rubber
Flap Side)
Carrier Arm
Assy.
Direct Behind Position
Offset Position

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Figure 3: ATV Tongue Assembly
OPERATIONS AND ADJUSTMENTS
This safety alert symbol is used to indicate safety instructions. Follow
these instructions to avoid personal injury and/or property damage.
Read and follow all instructions in this manual and the attached engine
manual.
WARNING: Do not allow anyone to operate this equipment who has not fully read and
comprehended the safety manual and who has not been properly trained in the safe
operation of the equipment.
WARNING: Operator should be familiar with all functions of the unit.
A. TONGUE CONFIGURATIONS AND ADJUSTMENTS
WARNING: Shut off the engine and allow the mower blades to come to a complete stop
before adjusting the tongue.
The hitching system is designed so that the rough cut mower can be pulled directly behind a tow
vehicle or offset to the left or right. See Figure 4.
Note: When pulling the mower directly behind, the hitch pivot should be fastened on the right
carrier arm for maximum maneuverability. See Figure 2. When pulling the mower in
the offset position the hitch pivot can be fastened on either the right or left carrier arm.
See Figure 2.
Wire Lock Section of
Wire Lock Pin
(Placed Back From
Direction of Travel)
5/16” Wire
Lock Pins
Direction of Travel
Screw Pin Shackle
Clevis
Tongue
Shift Tongue Left or Right
Between Holes

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The tongue is equipped with a screw pin shackle clevis to provide movement in all directions on
rough uneven ground. To prevent loss of the screw pin due to vibration or debris, place the screw
pin through the tow vehicle hitch and clevis and turn the screw pin until snug.
The tongue is designed to adjust from left to right within the hitch pivot. This allows the mowers
position to be varied behind the tow vehicle. This is accomplished by pulling the 5/16” wire lock
pins out and choosing two other hole locations on the tongue. See Figure 3.
Figure 4: Rough Cut Tow Behind Towing Suggestions
B. ADJUSTING CUTTING HEIGHT
WARNING: Shut off the engine and allow the mower blades to come to a complete stop
before adjusting the cutting height.
Figure 5: Adjusting Rough Cut Mower Cutting Height
Offset
Directly Behind
Measure This Distance
and Add 1-5/16” to get
Cutting Height
Cutting Height
1-5/16”
Smooth Surface
Lower Edge of
Deck
Mower Blade
Adjustment Crank: Roughly 6
turns equals 1.0”

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The cutting height can be adjusted in a range from 2.0" to 8.0". This is accomplished by turning
the height adjust cranks on both sides of the mower. See Figure 5. Turn the cranks clockwise to
raise the mower cutting height and counter-clockwise to lower the mower cutting height.
DANGER: Shut off tow vehicle engine and allow mower blades to stop completely before
attempting to measure the cutting height.
Adjust the mower as follows:
1. Pull the mower on to a smooth, level surface.
2. Adjust the mower evenly from side to side by measuring to the ground from the lower edge of
the mower deck. The desired height will be the distance from the ground to the outside lower
edge of the mower deck plus 1-5/16”. The mower blade cutting edge is 1-5/16” above the
outside lower edge of the mower deck.
Note: If the height adjust cranks do not turn easily, the pivot bolts holding the carrier arm
assemblies and height adjust screw may be too tight. Loosen the pivot bolts slightly to
allow easier pivoting. Care should be taken not to loosen too much or excess wear and
flexing may occur. Greasing the threads may also allow greater ease in adjustment.
Note: After leveling mower deck, quick field adjustment can be completed by counting crank
turns. Roughly 6 turns will equal 1” of vertical movement.
The adjustment crank may unturn due to vibration. This will allow the mower’s cutting height to
change. The crank can be secured by folding it down between the adjustment nut tube and the
upper pivot support. See Figure 6.
Figure 6: Securing Crank While Not In Use
Adjustment Crank
Carrier Arm
Adjustment Nut Tube
Upper Pivot Support

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C. STARTING ENGINE
WARNING: Set parking brake on tow vehicle.
Attach mower tongue to tow vehicle.
WARNING: Do not start rough cut mower unless it is attached to the tow vehicle.
Turn on the fuel shut off valve (red colored rotating knob) located inline on the fuel hose. The off
position on the valve is when the red handle lines up with the “O” symbol.
Set the choke to the desired position.
Set the throttle at approximately half throttle.
Start engine and allow engine to warm up.
Set engine speed at about half throttle and engage mower blades clutch handle. (The clutch
handle is located at the front of the mower under the engine.)
Note: Some belt squealing may occur on engagement. This is normal for a manual clutch
engagement design.
CAUTION: If the mower’s engine dies while in use, remove the rough cut mower from the
uncut area before attempting to engage the clutch. Inspect the blades for any obstructions
that may prevent blade engagement. Failure to follow these instructions may result in
premature clutch and belt failure or a fire.
Adjust engine speed to full throttle.
D. SHUTTING OFF ROUGH CUT MOWER
WARNING: Shift to neutral and set the parking brake before dismounting the tow vehicle.
Slow the engine speed down and disengage the clutch handle.
Allow engine to cool down for a short time before moving the ignition switch to the off position.
Turn off the fuel shut off valve (red colored rotating knob) located inline on the fuel hose. The off
position on the valve is when the red handle lines up with the “O” symbol.
E. MOWER OPERATION
DANGER:Keep hands, feet, hair and clothing away from moving parts.
CAUTION:Clean or replace any safety signs that are not readable or damaged.

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WARNING: Remove all objects from the work area that might be picked up and thrown by
the blades.
WARNING: Do not mow when children and others are around.
WARNING: Do not fill fuel tank while engine is running or hot.
WARNING: Keep all safety shields and deflectors in place during operation.
CAUTION: Remove grass build up from under safety shields before each use. Do not
remove safety shields while engine is running. Dry grass build up around belts and
sheaves can cause fires.
WARNING: Shut off engine before disconnecting the mower from the tow vehicle or
attempting to move the wing mower by hand.
WARNING: Never carry children or passengers.
WARNING: Do not allow children to operate this machine.
CAUTION: Slow down and watch the ends of the mower when making turns so objects
are not struck and/or run over.
WARNING: Look down, to the sides, and behind before and while backing to avoid
backing over something or someone. Care should also be taken while backing so that the
wing mower or mowers do not jackknife and damage hitches.
WARNING: Stop the mower blades on the mower if the tow vehicle becomes stuck or
stops going forward because of loss of traction. Shut off the engine on the mower before
attempting to push or pull the tow vehicle.
Listen to the rough cut mower engine while mowing. The engine should run free and not work too
hard. Working the engine too hard will cause overheating and premature failure.
CAUTION: If the mower’s engine dies while in use, remove the rough cut mower from the
uncut area before attempting to engage the clutch. Inspect the blades for any obstructions
that may prevent blade engagement. Failure to follow these instructions may result in
premature belt failure or a fire.
Do not allow material to build up on the air inlet to the engine cooling system. Special care should
be taken to make sure the engine is getting enough inlet air. Do not allow the engine cooling fins
under the shroud to be blocked. If air flow over the engine is restricted, the engine could
overheat.

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F. DRIVE BELT REMOVAL AND TENSION – Refer to Figure 7
WARNING: Shut off engine and allow mower blades to stop turning before making any
adjustments or repairs.
Remove the safety shields.
Loosen the nuts on the spring-loaded idler; adjust bolt until the belt can be slipped off the idler and
drive sheaves.
Slip the belt down under the drive sheave and off the blade spindle sheaves.
Install the new belt and then adjust the tension as follows: See Figure 7. Take special care to
make sure that the belt is placed between the brake stud and the idler pulley.
With the clutch engaged, adjust the nuts on the spring-loaded idler adjuster bolt until the length of
the spring is between 2-3/8” and 2-1/2”. This is the initial belt break in spring length. When the
belt is broken in after several hours of mowing, the running spring length should be between 2-
5/8” and 3-1/8”. For maximum belt life, periodic checks every 3-4 hours should be done to make
sure the spring length has not exceeded the recommended running length.
Note: Failure to periodically adjust the belt tension will result in severe belt wear and
premature belt failure.
This model comes with a belt brake, which is a safety feature that stops the blades from turning
after the clutch is disengaged. The only time the brake should be in contact with the belt is when
the clutch is disengaged.
CAUTION: The brake stud must be adjusted. If the brake stud is not adjusted correctly,
the blades will still spin even though the clutch may be in the disengaged position. Always
shut mower engine off before servicing.
Periodic brake stud inspections should be performed every 10 hours. In more severe cutting
conditions, more frequent inspections may be necessary. There are two parts to inspecting the
brake stud. Those two inspections are the disengaged spring length and brake stud clearance.
Note: It is quicker to perform the disengaged spring length and brake stud clearance
inspections if done simultaneously.
Disengaged Spring Length:
This inspection must be performed to make sure that there is proper braking force to prevent the
blades from spinning when the clutch is in the disengaged position. With the clutch in the
disengaged position measure the spring length. The spring must be between 3-1/4” and 4” to
provide the appropriate braking force. If the spring length is to long it will be necessary to adjust
the brake stud closer to the belt. If the spring length is to short it will be necessary to adjust the
brake stud further away from the belt. To make brake stud adjustments loosen the bolt on the top

12
of the brake stud and slide the brake stud in the slot. When the proper disengaged spring length
is achieved, tighten the bolt on the top of the brake stud. For this procedure do not adjust the
spring length. The spring length should only be changed when adjusting the belt tension.
Brake Stud Clearance:
This inspection is necessary to prevent over-braking. With the clutch engaged, check to make
sure that there is at least 1/2” of clearance between the brake stud and the belt. If the clearance
is less than 1/2” then it will be necessary to adjust the brake stud away from the belt. Keep in
mind that the disengaged spring length must stay between 3-1/4” and 4”.
CAUTION: If brake stud is not set in correct position, under-braking or over-braking may
occur. If over-braking occurs, premature belt failure or a possible fire could occur due to
excessive friction and overheating.
Figure 7: Belt Pattern, Spring Adjustment, and Brake Adjustment
No Less Than 1/2” Clearance With
Clutch Engaged
0” With Clutch Disengaged
Brake Stud
Initial Spring Length (New Belt):
2-3/8” to 2-1/2”
Running Spring Length:
2-5/8” to 3-1/8”
Disengaged Spring Length:
3-1/4” to 4”
Clutch Arm
Engine
Front
Clutch Engagement
Only Include
Spring in
Measurement

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G. MOWER BLADE REMOVAL, BALANCING & INSTALLATION
CAUTION: Sharp blades can cause bodily injury if not handled properly.
When removing the blade, it is recommended that a block of wood be placed between the blade
and the underside of the mower deck. This will allow the removal of the blade without the need to
hold the blade by hand.
CAUTION: Always balance the mower blades each time they are sharpened.
Out of balance mower blades cause excess vibrations which lead to premature bearing failures,
bolts coming loose, and overall deterioration of the wing mowers.
CAUTION: Always properly tighten the blade bolts to the specified torque. Failure to do so
can lead to unwanted loosening of the blade and damage to the blade holding saddle.
The Model MR55B uses the Kunz Engineering Part # (202141) blade bolt. This particular hex
head bolt is a 3/4” – 16NF x 1-1/4” long, grade 5 and it’s proper torque is 300 ft-lbs.
To ease in the blade installation process, use the same block of wood and method used during
the removal of the blades.
H. LUBRICATION
There are three lubrication points on the rough cut mower -- one spring-loaded idler pivot and
two caster wheel pivots. Lubricate at approximately 10 hr. intervals or more often as required in
dusty conditions.
I. STORAGE
Turn off the fuel shut off valve (red colored rotating knob) located inline on the fuel hose. The off
position on the valve is when the red handle lines up with the “O” symbol. If the mower is stored
outside, the engine should be covered to prevent water from getting inside the engine during
heavy rainstorms. See the Engine Manual for additional information.
J. EPA EVAPORATIVE COMPONENTS
This mower has been designed and built to meet all current EPA regulations. Any modification to
the fuel tank, fuel lines, vapor hose, fuel cap, roll-over / fuel vapor valve, carbon canister
(California Only) and hose clamps are prohibited. Replacement evaporative components should
be purchased from Kunz Engineering. Any questions about EPA regulations or evaporative
components can be directed to Kunz Engineering Inc. at 815-539-6954.

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ACREASE ROUGH CUT MOWER SPECIFICATIONS
Model
MR55B
ENGINE:
Engine Make Briggs & Stratton
Engine Model Commercial Turf OHV
Cylinders 2
Cycles 4
Crankshaft Vertical
Engine HP 23
Bore 3.12"
Stroke 2.89"
Displacement 44.2 cubic inches
Oil Capacity 2 U.S. qt
Crankshaft Dia. 1.0"
Key Slot 1/4"
Crankshaft Length 3.15"
Threaded Hole in End of Crankshaft 7/16-20
Engine Mounting Bolts 5/16-18x1.50 Through Bolt
Starter Electric
Choke Manual
MOWER:
Fuel Tank 3 Gal.
Effective Cutting Width 57"
Deck Construction 10 ga. Welded steel
Cutting Height 2" to 8"
Height Adjustment 2 Cranks
Rear Wheels (Fixed) (4 ply Turf Pnuematic) Two 15/600 x 6
Front Wheels (Caster) (4 ply Turf Pnuematic) Two 5.30/4.50 x 6
Blade Dia. 2-30"
Engine Speed, Blades Running 3600 RPM
CLUTCH TYPE
Engagement Speed Manual
DIMENSIONS
Length 108"
Width 60"
Height 29"
Weight 580 lbs.
HITCH
Hitch Type ATV Tongue
TOUCH-UP PAINT COLOR Pewter Gray, Krylon #1606

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ACREASE ROUGH CUT MOWER PARTS LIST
Item Part # Description Quantity
1202141 Blade Bolt, .75"-16UNF x 1.25" 2
2214030 Cup Washer 6
3216002 Wire Lock Pin, .31" x 2.50" 2
4216009 Screw Pin Shackle Clevis 1
5222005 Worm Drive Hose Clamp (7-7/8" to 9-1/8" Clamping Dia.) 2
6222012 Single Split Collar (1" I.D. x .1/2" Thick) 2
7225005 Compression Spring, 4.50"L x 1-3/32" O.D. x .125" Wire dia. 1
8226012 Offset Wheel Assy. (15/600 x 6, 2 Ply Turf) 2
8226014 Offset Wheel Assy. (15/600 x 6, Urethane Foam-Flatproof) Optional
9226013 Centered Wheel Assy. (5.30/4.50 x 6, 2 Ply Stud) 2
9226015 Centered Wheel Assy. (5.30/4.50 x 6, Urethane Foam-Flatproof) Optional
10 238004 "V" Belt, .62" x 95.9" O.C. 1
11 241001 Flat Idler, 4" O.D. x 3/8" Hole 1
12 241009 Flat Idler (Steel), 4" O.D. x 1/2" Hole 1
13 241010 "V" Sheave, 5" Dia. 1" Bore 1
14 243010 Plastic Bearing, 1-3/8" O.D. x 1.00" I.D. 4
15 243015 Precision Sealed Wheel Bearings (2" O.D. x 1" I.D.) 8
16 258022 Spindle Assy. 2
900075 Spindle Shaft (1)
900160 Housing Assy. (With Two Bearings) (1)
243006 Bearing (6206 w/ Trash Guard Seals) (2)
600271 Bearing Spacer (3.33" Long) (1)
241008 Sheave, (7-1/2" Dia., B-Section) (1)
17 259002 Offset Mower Blade, 2-1/2" Wide, 30" Long, 3/4" Hole 2
18 260004 Roll-Over / Fuel Vapor Valve (Includes Rubber Gromet) 1
19 264000 Solenoid 1
20 264003 Hour/Tack Meter Optional
21 264010 Ignition Switch 1
22 269009 Throttle Control, 27" 1
23 269010 Choke Control, 27" 1
24 275001 Control Panel Decal, Starting Instructions 1
24 275002 Warning Decal General 1
24 275003 Danger Decal, Cut Finger 2
24 275011 Clutch Engagement Decal 1
24 275007 Warning Decal, Belt Sheild 2
24 275019 Name Decal,Kunz 1
24 275021 Name Decal, AcrEase 1
24 275022 Name Decal, 57" Rough Cut 1
25 277002 Rubber Gromet 6
26 277011 Handle Grip 1
27 277035 Gas Cap - Audible Click/Tethered, Non-Venting 1
28 277036 Carbon Canister - 300cc (California Only) 1
29 277040 Fuel Tank, 3 Gal., 3-Layer EPA Certified 1

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Item Part # Description Quantity
30 600071 Spacer, 1.38" O.D. x 1.33" Wall x 2.19" Long 1
31 600126 Flap Retainer Strip 1
32 600133 Belt Sheild 2
33 600136 Brake Stud 1
34 600142 Upper Pivot Support 2
35 600143 Safety Belting 1
36 600146 Crank Arm 2
37 600172 Engine Support Bracket 1
38 600189 Idler Spacer Block 1
39 600290 Canister Support (California Only) 1
40 600294 Clutch Arm 1
41 600305 Control Panel 1
42 600306 Tank Support 1
43 900049 Battery Box Assy. 1
44 900058 Hitch Pivot 1
45 900061 Pivot Arm 4
46 900062 Height Adjust Nut 2
47 900066 Screw Adjuster 2
48 900069 Mower Deck 1
49 900082 Tongue 1
50 900106 Carrier Arm 2
51 900148 Caster Fork 2
52 900193 Idler Arm Assy. 1
243016 Bronze Bearing, 5/8"I.D. x 3/4" O.D. x .75" Long 2

17
ACREASE ROUGH CUT MOWER PARTS
12
3
4
5
7
9
1
2
13
16
17
21
19
20
22
14
25
27
26
29
31
32
10
15
35
34
37
30
41
43
44
45
46
24
47
48
50
51
49
42
38
23
33
8
6
11
18
28
36
39
40
52

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OPTIONAL EQUIPMENT
OPTIONAL WETLANDS KIT
The optional wetlands kit features an extra set of tires for added ground support in soft or water
saturated areas. The following are applications and features that the wetlands kit works best in.
•Great for wetlands or marshy areas that stay wet all year around.
•Works well in combination with small personal amphibious vehicles or tracked ATVs.
•More than doubles the tire surface area in contact with the ground.
•Very easy to install bolt-on kit.
•Works on all existing and new rough cut mowers.
•The rough cut mower will not float with the wetlands kit installed. Water greater than 2-3" in
depth should be avoided.
•With the Wetlands Kit installed the minimum cutting height is 3.5” – 4”.
Wetlands Kit (Part # 003905)