no thrust

[bill6357]

I have a 1989 6HP model J6RCEC. All of a sudden, the engine produces no thrust in foward. Reverse is unaffected. When I shift into forward, the prop turn slowly but produces no thrust. I brought it to a mechanic, he put it in a barrel and it moves the water. Just not enough to move the boat. He said its not worth what it would cost to diagnose. Id like to try myself. any suggestions where to start?

[Solarman]

Is the motor revving up, but just not moving? Could be the prop is slipping (it is made to slip if it hits something), but if the prop has started to slip, either you buy a new one, or have that prop rebuilt at a prop shop (they straighten and rebuilds props).

I can't imagine anything else, if it runs fine in reverse, but not forward? Unless motor RPMs are different from reverse and forward?

Post back if need. Good luck.

[bill6357]

the engine is reving fully and producing full thrust in reverse. I removed the prop and see no sign of damage. A non marine mechanic offered this possibility: If the cam that turns the control rod from reverse to forward is cracked, the rod might not be fully engaging the gear in forward. I suppose I'll have to remove the entire power head to get at that part.

[Solarman]

Then I guess you are saying that your motor is NOT shifting into forward, instead of ” no thrust in forward”. Has anyone removed the lower unit recently? To change water pump, for example?

If yes, maybe the shift rod is slightly out of adjustment? Or, possibly got a little bent somehow?
If not, it's possible the adjustment slipped? If hearing a grating (gear slipping/ chattering) sound, it may be worn gear and shift dog?

If it is going into gear (forward) all the way, and motor is revving up, but not going forward, try a different prop. It's bound to be slipping in forward. Can mark prop at cotter pin, start then put in forward. If your mark is not exactly lined up just where you marked it with respect to the cotter pin, then your prop is slipping.

Good luck.

[bill6357]

I gave up

I brought the engine to a mechanic and this is what he found. This particular model year (aren't I lucky) Johnson changed design in the lower unit. The shaft incorporates a bearing device to engage the forward gear. That bearing wore a larger hole in the gear which provided some friction (so the prop would spin) but not enough to push the boat. Replacement parts exceed the value of the engine. Too bad. It runs beautifully

[JohnG28]

What do you plan on doing with the motor? That's a shame, we had an '88 or '89 Evinrude, loved that little motor. Blew lower unit and sat for years, then my dad gave away to some idiot before I could get my hands on it to fix. Picked up a '76 6hp Johnson and got it running well now, little cosmetic work left to finish but she's a good runner.

[JohnG28]

Too bad

What do you plan on doing with the motor? That's a shame, we had an '88 or '89 Evinrude, loved that little motor. Blew lower unit and sat for years, then my dad gave away to some idiot before I could get my hands on it to fix. Picked up a '76 6hp Johnson and got it running well now, little cosmetic work left to finish but she's a good runner. Sorry for the duplicate post, slow WiFi at hotel. Admin feel free to delete, sorry, new here.

[Crappie Cat]

I brought the engine to a mechanic and this is what he found. This particular model year (aren't I lucky) Johnson changed design in the lower unit. The shaft incorporates a bearing device to engage the forward gear. That bearing wore a larger hole in the gear which provided some friction (so the prop would spin) but not enough to push the boat. Replacement parts exceed the value of the engine. Too bad. It runs beautifully

In my humble opinion, replacement parts seldom exceed the cost of of replacing the motor. But you have to draw the line somewhere