Have a '65 Johnson FD-19 here. I assume a 20 would, but will a 25 horse of the same era bolt in the 18 hp's place? Thanks in advance for any insight gents.
Yes, the 22-cube 25hp powerheads will bolt up as a unit. Use the 25's carb, too. Might have minor issue with carb linkage placement where it comes through lower pan, but that can be rectified with a file.
Ha I was half asleep when I read your reply about the 25 hp carbs. I read Lee Roy's Ramblings article on the 18, 20, & 25 horse all being 22 cubic inches. Now the search for a carb from a 25. I wonder if changing the high speed nozzle would suffice; allowing it to drink more fuel.
Well so much for bolting on more hp with a carb upgrade. Wishful thinking at its best. Just have to keep an open eye for a 25 horse. Seems the bolt pattern could be different between the '65 18 & '69 25.
Nope - same bolt pattern. Simple swap if you find a COMPLETE 25 powerhead. As I noted above, about the only issue might be the carb knob placement through the pan...
