thanks for the response so these diesels are easier to start than glow motors?

i am now unsure of a suitible prop size because i have heard that diesels are designed to turn with less rpm and will swing a bigger prop up to 3-4" bigger infact!

is this correct?

i am aware that too small a prop will wear the liner out faster and bearings. but a prop too large will also induce damage to the bearings?

can any one recomend a prop as this engine is old i can not find any info online and have no instructions.

thanks Ben