If it is the Ultima engine with the alloy carburettor block then all you will need to do is replace the 'O' rings in the carby bowl as well as the one on the main jet.
Once you have cleaned the block and replaced the 'O' rings let us know if it will start.
Regards,
Bruce
Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.