Birchwood 22 engine

[qmackay]

I wonder if someone can help. I have a 1974 Birchwood Junior Inceptor 22 and am very happy with the boat. The boat is currently fitted with an old Volvo 115 and I am considering upgrading the engine and leg. With the Volvo 115, the boat will cruise at 6 knots and can reach 12 knots when pushed hard. I wonder if you can tell me the maximum horsepower I can fit to the Birchwood 22 and what top speed I should expect.

Will there be any major issues un upgrading the engine?

Many thanks in advice for your help.

 

[neale]

New, these were fitted with engines up to 170hp. The standard option was a 130hp which gave speeds up to 25knots. Would expect more from 115 that what you're getting but age may have taken its toll. Have you tried different props. Could have been re-propped for river use.

 

[brianrunyard]

Are you getting Max Revs? My AQ115, which I rebuilt a year ago, revs to 5000 rpm.
If it revs higher, could be under propped, (i.e. finer pitch for river use).
What's the all up weight of the boat?
What size prop have you got?