3 questions 79 Johnson 85 HP

[Berni Hoareau]

" Hi,

I have recently strip

" Hi,

I have recently stripped down the above engine to replace the top engine mount at the suggestion of my mechanic. I decided to do it myself so I could spruce it up a little, new paint job seals etc.

1st Question, during the rebuild we found a crack in the power head to exhaust housing adaptor, we repaired it with an engine block repair putty as itlooked too thin to weld, the putty is rated at 150 deg C. WILL IT LAST.

2nd question, The mechanic said the top engine mount was broken because the motor wobbled when you grabbed it and pushed, the deflection did seem excessive however after replacing the mount the deflection is still there. WHAT ELSE COULD IT BE?

3rd Question What should my motor rev too at WOT? It has a 13 1/4" prop with a 19 deg pitch, 85 HP Johnson V4 1979 Model.

Joe you helped me when I first bouhgt this boat i have spent a bit of money on it and it runns pretty well now, i'm just trying to fine tune it a bit.

Thanks for your help anyone who can.

Regards

Berni "

 

[joereeves]

"Berni.... Pertaining to quest

"Berni.... Pertaining to question #1, that depends on where the crack is but my guess is that it will hold up. I've patched a few small cracks in those adapter plates with gray "Marine Tex" and have not had one fail.

Question #2, Quite a few mechanics get fooled by that engine wobble, thinking it's the top motor mount The steering arm is connected to a shaft that travels down through the swivel bracket. The bottom of that shaft has splines on it that spline into the lower motor mount bracket. Either the splines on the shaft or the splines on the mount bracket are damaged. This allows the engine to wobble back and forth.

The cure is to remove the lower unit to get the shift rod out of the way, then remove the top 3/4" hex head motor mount bolts (again), (Have the engine supported by a hoist). Then remove the four (2 on each side) hex head lower motor mount bolts from the front portion of the bottom mount bracket.

This allows you to remove the complete engine, leaving only the transom brackets, swivel bracket, etc on the boat. Tilt the swivel bracket to its extreme up position. Remove the large nut that you see on the bottom of the steering arm shaft. This allows you to remove that lower mount bracket and to remove the complete steering arm so that you can inspect it. (Good Luck)

Question #3, The 1979 85hp Evinrude/Johnson specifications are: 85hp is hit at 4500 rpm. Full throttle operating range is from 4500 rpm to 5500 rpm... not to exceed 5500 rpm.

Joe

"

 

[Berni Hoareau]

" Thanks Joe, I'll check i

" Thanks Joe, I'll check it out. "