Need opinions on Electramatic

[royal0014]

Johnson RK-28B, 40hp Electramatic (1966) J2651698

Finally splashed the boat today, after 3 years of working on it. Grinning ear to ear. But (you knew that was coming, right?), at about half-throttle the prop-hub spun, or at least I hope that it did. Could not get the boat up on plane.

If I understood the manual right, an Electramatic works off clutch hubs and springs for gears. The spring(s) wrap around the prop shaft to provide propulsion, correct?? So, theoretically, if the prop hub DID NOT spin, what did, the clutch hub or the spring?

I know the prop hub did move some, because I put two parallel marks on the nose cone and prop before putting in the water. After it spun once or twice I stopped to check, the marks had moved about an inch. It spun a couple more times, and back on the trailer the marks might have moved to 1 1/4 inches. Doesn't seem like much movement for the amount of freespinning the engine did. At one point, when 'it' spun, I had to shift to neutral and wait for the RPM's to back down to idle before I could go again.

I'll have to call tomorrow about repairing the prop. I have found new props on the www for < $100. I have also found the gearcase parts : frnt clutch hub $135, rear for $89. The springs are nearly $400 each

I really, really hope the problem is the propeller. What do ya'll think?

 

[tx1961whaler]

Re: Need opinions on Electramatic

Usually a spun prop slips when you're really getting on it, like over half to 3/4 throttle. Most of the time (not always..) you can get the boat to half throttle before it slips. Was yours seeming to slip at low RPM's?

 

[royal0014]

Re: Need opinions on Electramatic

It seemed to vary around 1/2 throttle, a little more or little less. At one point I had it slightly under 1/2, had been cruising along for quite aways when it just let go suddenly, without being provoked....

 

[ondarvr]

Re: Need opinions on Electramatic

Its just a rubber sleeve in the hub, the more it slips, the more easily it will slip, so if it moved at all its bad. There's no way of telling how many times it spun around before stopping in the current positon, most likely several thousand times.

 

[tashasdaddy]

Re: Need opinions on Electramatic

prop shop can rehub it, or buy a new one.

 

[royal0014]

Re: Need opinions on Electramatic

Yep, gonna get the prop fixed or buy new.

Still hoping there's Electramatic guru's out there that can answer my Q's about the clutch hubs and springs. Don't really have $400 for a spring.

"Hello, is there anybody in there, just nod if you can hear me..."

 

[F_R]

Re: Need opinions on Electramatic

According to the official manual, if the clutch slips, replace both the hub and spring.

But before you do that, always check it out electrically. Low voltage will make it slip too. So will the wrong oil.

But it doesn't matter at this point, because your prop hub obviously is the culprit.

 

[royal0014]

Re: Need opinions on Electramatic

Boy, that prop is way worse shape than either of mine

Fairly sure it's not low voltage, ran new wires myself. Though I will double-check when I get it out again.

Absolutely positive it's not oil related. OMC type C or nothing.

Thank You for the response FR. I'll be back with an update....