How to tell whether your reel mower needs sharpening or simply re-adjusting — the factory guide to correct cutter setting, including the newspaper test for checking the cutting cylinder against the bottom blade. Applies to every Scott Bonnar petrol and electric reel-type mower.
- ModelsAll Scott Bonnar petrol and electric reel-type mowers
- Pages4
- Publication750-15-0
Download the original PDF (0.7 MB)
Read it here
Every page of the original is reproduced below — no download needed.
Full text of this manual
This is a full transcription of the Scott Bonnar folder 750-15-0, issued with petrol and electric reel-type mowers. It is short, but it answers the single most common question about these machines: why is my mower tearing the grass instead of cutting it?
Like any precision equipment, your Scott Bonnar mower must be correctly adjusted to ensure peak performance.
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 illustration shows a gap between the cutting cylinder and the bottom blade — the condition to avoid.
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 illustration shows the cutting cylinder and bottom blade lightly touching — the condition to aim for.
* Refer to the manufacturer’s instructions for correct procedure for adjustment.
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.
Transcribed from Scott Bonnar folder 750-15-0. The scanned pages in the viewer above are the authoritative source. The advice about disconnecting the spark plug lead before turning the cylinder by hand is worth following on any reel mower, whatever its make.
Scott Bonnar Australia Pty. Ltd. (as printed)
The back panel lists where to go “for specialised service or spare parts” at the time of printing. Recorded here for historical reference only — none of these still trade.
- New South Wales: 357 Liverpool Road, Ashfield 2131 · Telephone 79 0222
- Victoria: 265 Huntingdale Road, Huntingdale 3166 · Telephone 544 1277
- South Australia: 33–47 Holland Street, Thebarton 5031 · Telephone 57 9155
- Queensland: 27 Ipswich Road, Woolloongabba 4102 · Telephone 91 2676
- Western Australia: 104 Belgravia Street, Belmont 6104 · Telephone 65 1288
- Tasmania: B. J. Electrics Pty. Ltd., 42 Wellington Street, Launceston 7250 (Telephone 2 1865) and 100 New Town Road, Hobart 7000 (Telephone 8 0377)