Danny, Many thanks for your info, servo is mounted rigid and rated at 18 kg so I've at least got that right. As for angles will have to check but again thanks for your help. Zen 7 came by way of Ebay [in would you believe a Vantex challenger as a straight engine swap] and yes you,re right , it is too powerfull but its all I've got to go in at the moment. Will swap engines with one in Mercury cat [260pum] if i can't get it right, and frighten myself to death with that instead!!