b77 Johnson 115hp question

[rb]

" My 115hp '77 Johnson has

" My 115hp '77 Johnson has 5 holes down on each leg of the casting of the engine mount brackets, with a lateral rod going from one bracket to the other and connecting the holes together.

What is the purpose/function of this arrangement? How do I figure out which set of holes is optimum for putting the rod through? "

 

[joereeves]

"RB.... Those holes and that r

"RB.... Those holes and that rod are to adjust your engine for the best possible angle of attack. If the engine is too far inwards, the bow will dig in as you increase speed. Too far out and the bow will ride high and will never plane out.

To get the best possible setting, have the boat on a trailer. Back yourself off from it a reasonable distance and sight the bottom of the boat (the keel) in a parallel angle with the cavitation plate (the plate just about the prop). That cavitation plate should be approximately 1" (not over 1") below the keel and on the same angle of attack. If you could lay a perfectly straight board on that plate, that board should be straight with and slightly lower than the bottom of the boat.

Joe

"

 

[rb]

" Excellent answer, Joe. Than

" Excellent answer, Joe. Thanks very much. I thought the function would turn out to be something similar to what you describe, but I had no idea how they get a rough initial setting or feel for which set of holes to pin. "