OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Reel-Type Mowers Ross's 30 Inch Conversion Electric to Petrol

Hi All
First post & I'm looking for any advice.
I have inherited a Ross's 30" mower from a local croquet club & looking to use with local cricket club to turf wicket prep. (all volunteer work). Its is a great bit of kit, Heavy & would love to be able to use it.

The 2hp 1440rpm electric mower has been removed as this isn't a option for my requirements
We have been gifted a Kohler 12hp engine that i estimate would put out 1400 rpm at idle & 3600rpm Full throttle

What are our options?
Can we fit the petrol engine & limit to 2000-2400 rpm?
Does it need to be geared Down?
Has anybody done this kind of thing?
Do i look for smaller engine?

We have many hands to be able to help us in the community i would just love some information
See Attached Images
Cheers
Rusty

Hi Rusty, welcome here lots of info gets thrown around and we try to help. Everything is doable and sounds like you have enough helpers. Going to be a bit of trial and error, looking at the size of your pulleys it looks maybe 2&1/2 inch to about 3&1/2 inch so that means your shaft would be turning probably at about 1000 rpm, bit of guessing but something like that. Probably the simplest way to get a clutch working is to have the motor on a pivot so it can allow the belts to slip. One step at a time and keep us updated.

Hello TVG Russell and Norm
I can't say I recognise a Ross Greens lawnmower.
I'm guessing it is a 1980s copy of a SB Queens.
Any information welcome.

Gearing is important!
The electric motor runs at 1400 RPM - quite low.
Because the Kohler is over-powered for the job, and runs to a higher RPM,
the Kohler needs to be run at idle - to roughly match the original performance.
I think that is do-able.

It is important that the RPMs match the original electric motor specification.
Over-heating of the reel - and pre-mature reel life will result from
any higher RPMs. Otherwise, clip rate and landroll speeds would be
way-too-high for efficacy.

This is not an ideal situation, but I understand economy is a factor here.
The Kohler running at normal operation speeds would require a change
in pulley sizes.

Please keep us informed.

All the best with this project.
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Jack

Morning All,

Google 'pulley ratio calculator' and first hit should be a helpful little page from blocklayer.com

It'll take the guesswork out of this and give you a very good idea of pulley sizes needed.

As long as the required pulleys can be physically installed I can't see why this won't work

Cheers,

All
Thanks for your responses. I will ensure I keep you updated on my progress
Cheers

I ended up with a Chonda 2:1 reduction gearbox. Had a mate fab up a cover and works a treat! This is a great bit of kit. Onto the next project

G'day TVG Russell

That's brilliant.
Many thanks for giving us such a great resolution to your story.

You are obviously talented, and your mate has done a great fab on the cover.

This is, as you say, a 'great piece of kit'.

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Jack