First you would need to know all the specs ,inner length, outer length etc to get one online and then trust the seller is telling you the correct information.
It's easier if you have an old cable to get one made at a bowden cable manufacturer.
Lots of places make them in Australia.
On some old mowers I've used a bike cable and just brazed one end and ground it down.
Silver solder would work well.
I have had some success just using normal solder but it can break off.
You can shorten down car fuel cap door release cables and boot release cables etc.
If you want a perfect cable get one made at a shop and if you want a cheap one modify a new one from something else.
If you don't have an old cable to get the sizes you could take the carby and throttle control to the shop and just tell them what length you want the black outer cable.
I've never had problems with these bowden cables ,apart from them breaking when they are worn out.
