Kunz AcrEase MR55K Datasheet

57” ROUGH CUT
MR55K
MR55B
OWNER’S MANUAL
With Assembly Instructions
For Models: MR55T, MR55B-17.5HP, MR55B-22HP & MR55K
KUNZ ENGINEERING, INC. / MENDOTA, IL 61342 / PH [phone]
1/07

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.
1

Flat Washer
Rear TireCarrier Arm
Assembly
Hex Nut and
Lock Washer Cup Washer
Bolt
Figure 1: Rear Tire Assembly Installation
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 PositionOffset Position
Figure 2: Assembly of Carrier Arm Assy., Hitch Pivot, and Tongue
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
Shift Tongue Left or Right
Between Holes
Tongue
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.
Read all Owners Manuals before using equipment.
Know locations and functions of all controls before operating the mower.
A. TONGUE CONFIGURATIONS AND ADJUSTMENTS
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.
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.
3

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.
Directly Behind Offset
Figure 4: Rough Cut Tow Behind Towing Suggestions
B. ADJUSTING CUTTING HEIGHT
Shut off the engine and allow the mower blades to come to a complete stop before
adjusting the cutting height.
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 e
q
uals 1.0”
Figure 5: Adjusting Rough Cut Mower Cutting Height
4

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.
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.
Adjustment Crank
Adjustment Nut Tube
Upper Pivot Support
Carrier Arm
Figure 6: Securing Crank While Not In Use
C. STARTING ENGINE
Set Parking Brake on tow vehicle.
Attach mower tongue to tow vehicle.
Do not start rough cut mower unless it is attached to the tow vehicle.
Set the choke to the desired position.
5

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.
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.
Adjust engine speed to full throttle.
D. SHUTTING OFF WING MOWER
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.
E. MOWER OPERATION
Clean or replace any safety signs that are not readable or damaged.
Remove all objects from the work area that might be picked up and thrown by the
blades.
Do not mow when children and others are around.
Do not fill fuel tank while engine is running or hot.
Keep all safety shields and deflectors in place during operation.
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.
Shut off engine before disconnecting the mower from the tow vehicle or attempting
to move the mower by hand.
Never carry children or passengers.
6

Do not allow children to operate this machine.
Slow down and watch the ends of the mower when making turns so objects are not
struck and/or run over.
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 mower
does not jackknife and damage hitches.
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.
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.
F. DRIVE BELT REMOVAL AND TENSION – Refer to Figure 7
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” and 2-1/8”. 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 2-1/4” and
2-3/8”. 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.
7

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.
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.
To adjust the brake, place the clutch in the engaged position. Loosen the bolt on the top of the
brake stud. Slide the brake stud in the slot until there is about 5/8” of clearance between the belt
and the brake stud. Tighten the bolt at the top of the brake stud. To ensure that the brake works
properly the spring length must be set correctly. With the clutch disengaged make sure the spring
length is no more then 2-3/4”. After the belt breaks in the clearance between the belt and the
brake stud should be around 1/2”. To prevent over-braking the brake clearance should be
checked every 3-4 hours.
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.
5/8” Initial Break-in Brake Setting
With Clutch Engaged
1/2” Running Brake Setting With
Clutch Engaged
0” With Clutch Disengaged
Brake Stud
Clutch Engaged
Spring Length 2-1/4”
to 2-3/8”
Clutch Disengaged
Spring Length No
Less than 2-3/4”
Clutch Engagement
Front
Engine
Clutch Arm
Figure 7: Belt Pattern, Spring Adjustment, and Brake Adjustment
8

G. MOWER BLADE REMOVAL, BALANCING & INSTALLATION
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.
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.
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 Models MR55K, MR55B and MR55T use 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 five lubrication points on the rough cut mower -- one spring-loaded idler pivot, two
caster wheel pivots, and two blade spindles. Lubricate at approximately 10 hr. intervals or more
often as required in dusty conditions. Lubricate the blade spindles 2-5 pumps every 50 hours.
(The bearings have trash guard seals to hold the seals in place during lubrication.) Lubricate with
a high grade of pressure gun grease.
Note:Do not over grease blade spindles. Blade spindles are initially greased at the factory.
Greasing before 50 hrs. may cause bearing seal damage which will result in premature
bearing failure.
I. STORAGE
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.
9

ACREASE ROUGH CUT MOWER SPECIFICATIONS
Model Model Model Model
MR55T MR55B-17.5HP MR55B-22HP MR55K
ENGINE:
Engine Make Tecumseh Briggs & Stratton Briggs & Stratton Kohler
Engine Model Enduro OHV 170-EXE Intek AVS OHV Intek OHV Command OHV
Cylinders 1 1 2 2
Cycles 4 4 4 4
Crankshaft Vertical Vertical Vertical Vertical
Engine HP 17 17.5 22 20
Bore 3.56” 3.57" 2.97" 3.03"
Stroke 3.00” 3.06" 2.89" 2.64"
Displacement 29.9 cubic inches 30.6 cubic inches 40.0 cubic inches 38.1 cubic inches
Oil Capacity 1.94 U.S. qt 1.5 U.S. qt 2 U.S. qt 2 U.S. qt
Crankshaft Dia. 1.0” 1.0" 1.0" 1.0"
Key Slot 1/4” 1/4" 1/4" 1/4"
Crankshaft Length 3.15” 3.15" 3.15" 3.15"
Threaded Hole in End of Crankshaft 7/16-20 7/16-20 7/16-20 7/16-20
Engine Mounting Bolts 3/8-16x1.00 Thread Rolling 5/16-18x1.50 Through Bolt 5/16-18x1.50 Through Bolt 5/16-18x1.50 Through Bolt
Starter Electric Electric Electric Electric
Choke Manual Manual Manual Manual
MOWER:
Fuel Tank 3-3/4 Gal. 3-3/4 Gal. 3-3/4 Gal. 3-3/4 Gal.
Effective Cutting Width 57” 57" 57" 57"
Deck Construction 10 ga. Welded steel 10 ga. Welded steel 10 ga. Welded steel 10 ga. Welded steel
Cutting Height 2” to 8” 2" to 8" 2" to 8" 2" to 8"
Height Adjustment 2 Cranks 2 Cranks 2 Cranks 2 Cranks
Rear Wheels (Fixed) (4 ply Turf Pnuematic) Two 15/600 x 6 Two 15/600 x 6 Two 15/600 x 6 Two 15/600 x 6
Front Wheels (Caster) (4 ply Turf Pnuematic) Two 5.30/4.50 x 6 Two 5.30/4.50 x 6 Two 5.30/4.50 x 6 Two 5.30/4.50 x 6
Blade Dia. 2-30” 2-30" 2-30" 2-30"
Engine Speed, Blades Running 3600 RPM 3600 RPM 3600 RPM 3600 RPM
CLUTCH TYPE
Engagement Speed Manual Manual Manual Manual
DIMENSIONS
Length 98” 98" 98" 98"
Width 60” 60" 60" 60"
Height 29” 29" 29" 29"
Weight 515 lbs 550 lbs. 580 lbs. 580 lbs.
HITCH
Hitch Type ATV Tongue ATV Tongue ATV Tongue ATV Tongue
TOUCH-UP PAINT COLOR Pewter Gray, Krylon #1606 Pewter Gray, Krylon #1606 Pewter Gray, Krylon #1606 Pewter Gray, Krylon #1606
10

ACREASE ROUGH CUT MOWER PARTS LIST
Item Part # Description Quantity
1 214021 Cup Washer 6
2 216002 Wire Lock Pin, .31" x 2.50" 2
3 216009 Screw Pin Shackle Clevis 1
4 222005 Worm Drive Hose Clamp (7-7/8" to 9-1/8" Clamping Dia.) 2
5 225003 Compression Spring, 3"L x 1-3/32" O.D. x .135" Wire dia. 1
6 226003 Offset Wheel Assy. (15/600 x 6, 2 Ply Turf) 2
7 226004 Centered Wheel Assy. (5.30/4.50 x 6, 2 Ply Stud) 2
8 238004 "V" Belt, .62" x 95.9" O.C. 1
9 241001 Flat Idler, 4" O.D. x 3/8" Hole 1
10 241009 Flat Idler (Steel), 4" O.D. x 1/2" Hole 1
11 241010 "V" Sheave, 5" Dia. 1" Bore 1
12 258015 Spindle Assy. 2
900075 Spindle Shaft (1)
600159 Sheave Spacer (1.98" Long) (1)
900078 Housing Assy. (With Two Bearings) (1)
243006 Bearing (6206 w/ Trash Guard Seals) (2)
600158 Bearing Spacer (1.41" Long) (1)
241008 Sheave, (7-1/2" Dia., B-Section) (1)
13 259002 Offset Mower Blade, 2-1/2" Wide, 30" Long, 3/4" Hole 2
14 264002 Solenoid (Only on Models MR55B & MR55T) 1
15 264003 Hour/Tack Meter Optional
16 264010 Ignition Switch 1
17 269000 Choke Control, 20" (Model MR55B-17.5HP & MR55T) 1
17 269007 Choke Control, 22.5" (Model MR55K) 1
17 269010 Choke Control, 27" (Model MR55B-22HP) 1
18 269001 Throttle Control, 15" (Model MR55B-17.5HP & MR55T) 1
18 269008 Throttle Control, 46" (Model MR55K) 1
18 269009 Throttle Control, 27" (Model MR55B-22HP) 1
19 275001 Control Panel Decal, Starting Instructions 1
19 275002 Warning Decal General 1
19 275003 Danger Decal, Cut Finger 2
19 275011 Clutch Engagement Decal 1
19 275007 Warning Decal, Belt Sheild 2
19 275019 Name Decal,Kunz 1
19 275021 Name Decal, AcrEase 1
19 275022 Name Decal, 57" Rough Cut 1
20 277002 Rubber Gromet 6
21 277010 Fuel Tank, 3.75 Gal. (Plastic)(Use Gas Cap 277013) 1
22 277011 Handle Grip 1
23 277013 Gas Cap (For Fuel Tank 277010) 1
24 600071 Spacer, 1.38" O.D. x 1.33" Wall x 2.19" Long (MR55B & MR55T) 1
24 600173 Spacer, 1.38" O.D. x 1.33" Wall x 2.25" Long (MR55K) 1
25 600126 Flap Retainer Strip 1
26 600133 Belt Sheild 2
27 600136 Brake Stud 1
28 600142 Upper Pivot Support 2
29 600143 Safety Belting 1
30 600146 Crank Arm 2
11

Item Part # Description Quantity
31 600189 Idler Spacer Block 1
32 900023 Control Panel 1
33 900049 Battery Box Assy. 1
34 900058 Hitch Pivot 1
35 900061 Pivot Arm 4
36 900062 Height Adjust Nut 2
37 900063 Clutch Arm 1
38 900065 Idler Arm Assy. 1
243005 Bronze Bearing, 1/2"I.D. x 3/4" O.D. x .75" Long 2
39 900066 Screw Adjuster 2
40 900069 Mower Deck 1
41 900071 Engine Support Bracket (Model MR55B-17.5HP & MR55T) 1
41 600172 Engine Support Bracket (Model MR55K & MR55B-22HP) 1
42 900073 Caster Fork 2
43 900079 Tank Support 1
44 900082 Tongue 1
45 900106 Carrier Arm 2
243010 Plastic Bearing, 1-3/8" O.D. x 1.00" I.D. 4
12

13
ACREASE ROUGH CUT MOWER PARTS
10
2
3
4
5
6
7
8
1
11
12
13
16
14
15
17
19
20
21
22
23
25
26
27
28
29
30
41
24
32
33
34
35
36
38
39
40
45
42
44
4331
18
37
9

SAFETY SIGNS AND LOCATIONS
275003 – Danger
Decal, Cut Hand & Foot
275007 – Warning
Decal, Belt Sheild
275002 – Warning
Decal, General
Serial # and Model #
Decal
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]
14

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)
15

OPTIONAL EQUIPMENT
OPTIONAL ELECTRIC LIFT KIT
The optional electric lift kit consists of all of the mounting hardware, brackets, electric actuator and
wiring with remote control panel.
•Great for constantly changing terrain and grass/brush heights.
•Allows for quick cutting height changes on the go from the seat of the tow vehicle.
•Raise up and over rocks and logs with ease.
•Heavy duty 1200 lb linear screw actuator made by Bear Linear.
•Works on all existing and new rough cut mowers.
Electric Lift Kit (Part # 003909)
16

OPTIONAL EQUIPMENT
OPTIONAL FLOATATION KIT
The optional floatation kit consists of one additional front and rear tire, mounting brackets and
hardware.
•Great for mowing around ponds and on rough uneven ground where scalping would normally
occur.
•Clamping style receiver allows for adjustments from side to side with both the front and rear
tires.
•Pinned receivers make for quick kit removal when not needed.
•Works on all existing and new rough cut mowers.
Part numbers needed for standard manual lift rough cut models.
Rear Floatation Kit (Part # 003907)
Front Floatation Kit (Part # 003908)
Cross Brace Tube (Part # 900110) (Purchase one brace for each front and rear kit)
Part numbers needed for rough cut models with the electric lift kit.
Rear Floatation Kit (Part # 003907)
Front Floatation Kit (Part # 003908)
17