Capnorv, Thank you very much for taking the time to reply with your help. I can't find the sizes in my manual but a yanmar
dealer has since advised that I need 2xM8 x65 and 1 xM8x 40. Both by 1.25 metric thread. Because of the limited access in this situation it is very difficult for me to do any measuring myself. Love that Avatar. We don't see them at all here in OZ. Mostly Northshore and Phantoms.I have a more modest Columbia
27 but as I do all my own anti-fouling
etc I couldn't handle any larger. Besides I have had her for
over 20 years and boats just grow on you.She's been everywhere and there's been nothing she couldn't handle. Thanks again.