Vibration on 78 Johnson 85 hp

[scully222]

I have a 78 Johnson 85 HP and when I put in forward to take off, it vibrates and struggles a little, then smooths out and takes off great. The boat is a 67 16 ft Starcraft alum. I guess I could live with it but don't want to cause any damage. Any ideas?

 

[licketdsplit756]

Re: Vibration on 78 Johnson 85 hp

Put It In Neutral. Engine Off Stand To The Side. Spin The Prop Look For A Bent Blade.also Make Sure It Is Tight And Has Not Loosened On You. I Have Seen Some Where The Keyway Was Almost To The Point Of Shearing Off. Due To Hitting Debrease In The Water.

 

[Chinewalker]

Re: Vibration on 78 Johnson 85 hp

Also, watch the dimple in the center of the propshaft as you spin the prop. Any wobble would indicate a bent propshaft...
- Scott