Hooroo to the guru.
Thanks to all the gurus who have helped me with very good advise.
I am happy to report the the Stihl Viking Ride-On is working as good as new.
I only had to take the carby off, clean it and re-assemble it.
Drain any oil/petrol and re-fill and it started right away.
I was ready to spend $840.00 for a new (probably Chinese) motor.
Money saved is money earned.
Thanks again, Mike, Joe and Grumpy.
Best regards from Lake Bolac
Frank