The full instruction book for the Scott Bonnar Model 590 Diplomat reel mower — handle locking, grassbox, starting, cutter setting, drive belt adjustment and belt replacement with the exact 12 mm and 1.5 mm clearances, plus 25 power lawnmower safety precautions.
- ModelsModel 590 Diplomat
- Pages8
- Publication1942823
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Full text of this manual
A full transcription of Scott Bonnar publication 1942823, the instruction book for the Model 590 Diplomat reel mower — a later belt-driven machine with a traction clutch.
Before starting
The instructions set out in this book refer to the mower only. Before operating your mower you should study the separate engine instruction folder supplied.
Caution. The cutting assembly of this mower is ruggedly designed for long life. However, the cutting blades are finely set for best cutting performance and care should be taken to avoid damage. A quick check to see the area to be mown is free of stones, heavy twigs or bones etc., will pay dividends in maintenance and good cutting.
Handle locking
When the mower is removed from the carton the handle will be in a folded position.
To lock the handle in the operating position, pivot the handle upwards. Lock in position by inserting the hexagonal setscrew into the threaded hole and tighten firmly using the adjusting tool supplied with the mower.
Grassbox
To attach the grassbox locate the ‘lipped’ section of the grassbox onto the bar at the bottom of the grass exit chute. Lift the grassbox slightly to slide the top of the grassbox over the retaining plate at the top of the grass exit chute.
To detach simply lift and pull back.
A visual indicator slot is located at the rear left hand side of the grassbox. When grass is seen to be filled to the indicator slot, the box is filled to maximum capacity; further cutting will allow grass to fall back into the cutter.
Never attempt to clear the cutter when engine is running.
Cutting height adjustment
Set cutting height by turning the adjuster knob to raise or lower cut as desired. Indicator rings are provided for visual indication of cutting height.
When adjusting for low cutting, do not set mower so low that the weight of the machine is taken on the bottom blade instead of the front roller. This would affect cutting, and also place excessive load on the engine.
Starting & operating instructions
For detailed engine starting instructions refer to engine leaflet.
Fill the fuel tank with standard grade petrol, always clean the opening of the fuel container and the tank before pouring. Always use a clean funnel or suitable pourer. Never refuel when engine is running or when it is very hot.
Ensure crankcase is filled to correct level with SAE 30 or 20/40W engine oil.
- Ensure spark plug lead is connected, and stopping switch is away from spark plug.
- Pull out choke. Hold the mower handle with the left hand to steady mower and pull the starter cord rapidly. When the engine starts, push in choke.
- When the engine starts, move the throttle control lever to obtain the desired engine speed.
- Squeeze the traction clutch lever.
- In thick grass it is advisable to pull the mower back onto an already cut area before re-engaging clutch.
Stopping procedure
Reduce engine speed to idle. Press stopping switch onto the spark plug and the engine will stop.
Adjustments
Cutter setting
To adjust the bottom blade take the adjusting tool supplied for this purpose, loosen the locknut (J) to allow movement of the bottom blade. Use the adjusting tool as a screwdriver and carefully turn the two adjusting screws (A) in a clockwise direction until the bottom blade lightly contacts the cutter blades.
Adjustment should be made by turning each screw a small amount, until the cutter is correctly set.
Adjustment is correct when the cutter lightly touches the bottom blade along its full length.
Hard pressure or uneven setting causes excessive or uneven wear on the cutting edges and also places undue load on the engine.
When the cutter is set correctly, retighten locknut (J) to lock the bottom blade in position.
Drive belt adjustment
Should the mower lose traction and cutter drive the drive belt will require adjustment. Proceed as follows:
- Remove the 2 retaining screws from the belt and pulley guard and remove the guard thus exposing the drive belt.
- Loosen the adjustment locknut (B) and screw the belt tensioning rod in until the distance of approximately 12 mm exists between the clutch lever and the handle grip when the lever is squeezed without using undue pressure.
- Retighten locknut (B) and replace belt guard.
When there is no adjustment left on the adjustment rod and the distance of 12 mm cannot be maintained due to belt stretch, a new belt must be fitted.
General maintenance
Air cleaner
The air cleaner must be regularly cleaned; refer to the separate engine instruction folder for cleaning instructions. Fine dust will pass through the pores and cause engine damage if not correctly maintained.
Oil change
Remove the cap from the fuel tank and place a clean tin under the lip of the fuel filler and lay the mower back on its handles allowing the fuel to drain out of the tank into the tin.
This prevents the fuel contaminating the air cleaner element which causes difficult starting.
Remove the oil drain plug from the crankcase. Hold a tin under the drain hole and tilt the mower forward to drain.
Replace plug and refill crankcase in accordance with instructions set out in the engine instructions folder.
General
All bearings are sealed and pre-lubricated for life. Bushes are nylon or self-lubricating and require no maintenance.
Occasionally check that grass and dirt are not blocking off the flow of cooling air through the flywheel screen and the cylinder head. This will cause the engine to overheat.
The mower is constructed of first-class materials but longer and more efficient service will be obtained if the mower is kept clean.
To obtain the best results from your mower, the cutter should be sharpened and set at least once each season. This can be arranged through any of our Branches or distributors.
Fitting a new drive belt
It is recommended that in the infrequent need of belt replacement that the mower is returned to an authorized Scott Bonnar service agent for correct fitting and adjustment.
The patented belt lifter device (C) which prevents clutch ‘creep’ relies on the correct amount of end play in the clutch cable, therefore particular attention must be paid to this adjustment when fitting a new belt.
The procedure for replacement of the belt is set out below.
- Remove belt guard cover.
- Loosen locknut (D), slacken off the belt adjustment rod (E) completely and remove the old belt. Fit new belt.
- Remove the drive shaft cover plate by pushing on the front to ‘spring’ the retaining clips from the locating holes.
- Remove the clutch cable retaining clip from the handle to allow the cable to move freely.
- Slacken off the clutch cable locknut (F).
Depress the belt into the engine pulley (G) and hold in this position while adjusting the clutch cable. The cable length adjuster (H) is screwed in or out until the cable has 1.5 mm free movement when grasped and moved up and down as illustrated. The free movement can be estimated by noting the amount the metal ferrule on the cable moves in and out of the adjuster.
At the same time the clutch lever must be in a fully released position and the cable end correctly located in the clutch lever bracket.
Retighten the adjuster locknut and replace cable clip.
Set the belt tension by adjusting the belt tensioning rod so that the distance of 12 mm exists between the hand grip and the clutch lever when the clutch is squeezed without using undue pressure.
Correct cutter setting is vital — proper care means less wear
1. Ragged, uneven cutting caused by poor cutter setting
If your mower is doing a ragged uneven job of mowing it does not necessarily mean that the blades need sharpening. In most instances it simply means that the cutting cylinder needs re-adjusting.
With use, the cutting cylinder and bottom blade very gradually wear away from each other, thereby reducing the cutting efficiency. The blades maintain a better edge so long as they are lightly touching the bottom blade. They become blunted and dull when they are no longer making contact, caused by the grass being “dragged” through and not cut cleanly.
The action of a Scott Bonnar reel type mower produces a scissor-like cut and therefore the cutting cylinder adjustment is all-important to the finished appearance of the lawn.
2. Smooth, even cutting effected by correct cutter setting
From time to time, depending on frequency of use, your mower will require adjustment of the cutting cylinder. The cutting cylinder must be adjusted to lightly touch the bottom blade along its full length. When adjusted correctly, a piece of newspaper should be cut cleanly when held against the bottom blade whilst revolving the cylinder by hand. When adjusting the cutting action of petrol mowers, be sure to remove the lead from the spark plug. This will ensure that the engine will not start when the cutting cylinder is turned by hand.
The correct procedure for cutter adjustment is set out in this book under “Cutter Setting”.
3. The front roller has nothing to do with the adjustment of the cutting blades
It merely serves as the adjustment for height of cut, allowing the cutter to pass across the grass at the desired height of cut.
Power lawnmower safety precautions
Reproduced in full from the back page. Most of it is as sound now as it was then.
- Know your controls. Read the owner’s manual carefully. Learn how to stop engine quickly in any emergency.
- Make sure the lawn is clear of sticks, stones, bones, wire and debris. They could be thrown by the blade.
- Stop the engine and disconnect spark plug wire before checking or working on the mower.
- Before using, always visually inspect to see that blades, blade bolts and cutter assembly are not worn or damaged. Replace worn or damaged blades and bolts in sets to preserve balance. Damaged blades and worn bolts are major hazards.
- Check all nuts, bolts and screws often; always be sure the mower is in safe operating condition. Use only replacement parts made and guaranteed by the original manufacturer of your mower.
- Add fuel before starting engine. Avoid spilling petrol and do not fill the tank while engine is running or while you are smoking.
- Do not mow whilst people, especially children, or pets are in the mowing area.
- Never use the mower unless the grass catcher, or guards provided by the manufacturer, are in position.
- Do not mow barefoot or in open sandals. Wear long trousers and heavy shoes.
- Disengage all blade and drive clutches before starting.
- Start the engine carefully with feet well away from the blades.
- Do not operate engine in a confined space where exhaust fumes (carbon monoxide) can collect.
- Stop the engine whenever you leave the mower, even for a moment.
- Stop the engine before pushing mower across gravel drives, walks or roads.
- Do not allow children or people unfamiliar with these instructions to use the mower.
- On slopes or wet grass, be extra careful of your footing.
- Never cut grass by pulling the mower towards you.
- Never use an electrically powered mower in the rain or when grass is wet.
- Be extremely careful when using a riding mower on slopes.
- Never leave wind-up starters in a wound condition.
- Do not over speed the engine or alter governor settings. Excessive speed is dangerous and shortens mower life.
- It is advisable to wear suitable eye protection when operating a mower.
- Turn the fuel off at the conclusion of mowing and reduce the throttle setting during engine run-out.
- Store fuel in a cool place in a container specifically designed for the purpose. In general, plastic containers are unsuitable.
- Never pick up or carry a mower when it is operating.
Warranty (as printed)
Scott Bonnar Limited undertakes to repair or replace without charge to the original purchaser any part of the mower which shall fail within a period of twelve months from the date of sale to the original purchaser where in the opinion of Scott Bonnar Limited such failure is due to any defect in the material or workmanship embodied in the mower.
Where the mower is used for other than domestic purposes, the warranty shall continue for a period of three months only.
The obligations of Scott Bonnar Limited shall extend only to repairing or replacing such part at its service branches or at the premises of an authorised service representative.
Conditions
- All transportation charges on, and damages and loss incurred in connection with the transportation of, mowers or parts submitted for repair under this warranty shall be borne by the purchaser.
- This warranty does not apply to defects which, in the opinion of Scott Bonnar Limited, are caused by accident, wear or tear, misuse or neglect, or by interference with the construction of the machine as completed by the manufacturers.
- Items such as cleaning of spark plugs and carburettor jets, adjustment of cutters etc., are not covered under this warranty. While the services of our representatives are available to carry out minor adjustments, a charge is made to cover travelling and time involved.
- Warranty in respect of the engine is as laid down by the engine manufacturer.
This warranty is reproduced for historical completeness only. It expired with the original purchaser decades ago and confers no rights today.
State branches and service centres (as printed)
Scott Bonnar Sales Pty. Ltd., member: Challenge Corporation Ltd., group of companies.
- Queensland: 27 Ipswich Road, Woolloongabba 4102 · Telephone 91 2676
- New South Wales: Clyde Industrial Estate, 321 Parramatta Road, Auburn 2144 · Telephone 648 0431
- Victoria: 265 Huntingdale Road, Huntingdale 3166 · Telephone 544 1277
- South Australia: 33–47 Holland Street, Thebarton 5031 · Telephone 43 9155
- Western Australia: 104 Belgravia Street, Belmont 6104 · Telephone 65 1288
Transcribed from Scott Bonnar publication 1942823. The scanned pages in the viewer above are the authoritative source.