89 Johnson 110 Slips out of gear

[j110gman]

I have a '89 Johnson 110 short shaft that seems to slip out of gear around 3000 RPM, just as the boat starts to get up on plane. The boat is a 1990 Four Winns Horizon, which originally had a longshaft 150 on it. This is my first boat and had to rebuild the engine. After doing so is when I noticed the slipping since I can not get it to full throttle before it comes out of gear. So I found the gear oil milky so dropped the lower gear, replaced all seals (water pump while there) and the clutch dog (had only minor wear but I figured why not since it's opened up). Went back out to the lake and same problem. My only thought at this point is that the engine sitting to high compared to the bottom of the boat is basically loosing its "bite" on the water allowing the clutch dog to come out. It doesn't have a hard thud or anything it just revs to around 3000 RPM and then just as the boat starts to plane it revs to 5000 RPM and has no thrust. I have to shift back down to neutral to get back in gear and then it works fine until i go to that same point. Is this a possibility with being short on the transom or am I thinking wrong. The cavatation plate is about 4 inches above the bottom of the boat. Any ideas are helpful.
Thanks,
Greg

 

[bruce--69]

Re: 89 Johnson 110 Slips out of gear

Your probably cavitating, which means your prop is coming out of the water. You cant put a short shaft motor on a long shaft transom. If it was your clutch dog and gear were slipping, it would feel like you hit something in the water, a quick 'thump'.
The other thing is your prop hub could be slipping within your prop, but your more than likely coming out of the water.

 

[wilde1j]

Re: 89 Johnson 110 Slips out of gear

Prop slipping:
1. Mark inner and outer hubs with indelible marker
2. Run boat to planning speed
3. Compare marks ? if they?ve moved relative to each other, hub is slipping
4. Remove prop
5. Take it to a propeller shop and have it rehubbed

 

[j110gman]

Re: 89 Johnson 110 Slips out of gear

I did check the prop and the hub was not slipping, forgot to mention that, but when cavitating can the clutch disengage?

 

[bernd64]

Re: 89 Johnson 110 Slips out of gear

most of the time wen the cluchdog is coming out off gear you will hear a banging noise . i bet you caching air on the prop. the cavitation plate has to be in line with the kiel line of the boat to make thinks work the way it sopost to.

 

[j110gman]

Re: 89 Johnson 110 Slips out of gear

Well good news .. more or less.
I took a chance and bought a manual jack plate, mounted it reverse and can now lower the engine almost 2 full inches before the steering arm starts to get pinched. Not the most ideal solution but took it out on the lake tonight and was able to get it up on a plane and reach WOT. Topped out at 4500 and almost 35mph (on gauge so not sure if accurate) with stock prop.

Bad news, have to raise it back all the way to get the motor clear to tilt for road travel but I'll still take it over not being able to plane, only takes about 5 minutes to grab the ratchet and lower or raise.

But a fix for $240 to get out for the rest of the season.

G