'88 Force 85 HP Shift Linkage

[mobilehomie]

I have an 85 HP Force engine on an '88 Spectrum (aluminum hull by Bluefin). Engine runs great, but yesterday on the water, we were getting a violent "bang" at random intervals (five to twenty seconds) only in forward motion. At first I thought there was a miss, but it being so violent, I am thinking the linkages are putting it into 'N' and then back into "F". What leads me this way is as of this season I sometimes have to jiggle the shifter handle into "F" before it will start (neutral safety thing), and also new this season when I "pop" it into gear it will sometimes grind until I push the selector forward far enough to accelerate. I had a new block or power head put on prolly six years ago and suspect some linkage didn't get properly set or tightened up

 

[mobilehomie]

Bump

I have not done anything yet with this problem... Was wondering if anyone could verify shift linkage would cause this violent bang. Or do you think there could be something wrong with the lower unit.

 

[Frank Acampora]

Yes, the bang is the lower unit being forced out of gear then popping back in. this can be due to worn dogs on both the dog clutch and gears or simply a mis-adjusted shift linkage. SO: the first thing to try is adjusting the linkage. Now: DOWN on the linkage is forward gear so you want to go under the transom clamps and remove the cotter pin. Then spin the lower rod counterclockwise one turn to raise it a bit. Try one turn, replace the cotter, and see if that helps you should feel the prop locking in both directions when you put the engine in gear. If it ratchets when you turn the prop forward but locks when you turn it backwards, then you can still raise the rod a bit. correct adjustment is prop locking in both directions BUT you can not feel dragging as you wiggle the prop back and forth. Too much forward bias puts a load on the drive dog clutch and it will ride against the face of the gear creating drag.

 

[mobilehomie]

Thank you Frank! I most certainly would have messed with the cables under the engine cover. It's nice to know I can check this with out launching in water.