TOPIC: 65 40hp spinout problem

I have a 1965, 40 hp Johnson outboard with electric shift. When it runs fine at idle and a litle above, however when I try to open it up, the propeller disengages and the engine revs very high. Usually occurs in the 2000 to 2500 rpm area. It is above my knowledge and the local mechanics haven't figured it out. Is anyone familiar with this and have any ideas on how to fix it? Thanks

thetudor wrote:

Is anyone familiar with this and have any ideas on how to fix it? Thanks

Yes, the rubber hub in your prop is likely "spun". You can confirm this by marking the aluminum body of the prop with a "sharpie" or other suitable means, also make a match-mark on the bronze prop insert. Take the boat out, let the slippage occur, then check the match-marks. Pretty much guarantee that they will have moved.

If you have a local prop shop they could re-hub the prop, but props for these are so plentiful you should be able to find one either on the Craigslist or eBay.

Here's a new prop at iboats for $106:

boatpropellers.iboats.com/Evinrude/40_HP_%281960-1976%29_11.50-Pitch_Propellers/43/?cart_id=299368508

And a pretty-new-looking 10" dia x 12" pitch prop on eBay for $75 shipped:



Note that if you do find that the prop isn't slipping, there may be something wrong with the electric shift lower unit. The spring could be slipping on the forward gear drive hub.

But typically on Selectric models, either there's a power problem that completely disengages the gearbox, or a spring breaks and there's no drive at all.

I'll bet on the prop hub slipping until proven otherwise!

HTH..........ed

Props $84 + $20 shipping I believe at PropCo.

propcopropellers.com/evinrude_Outboard_Prop.htm

vin, let me know if you need a prop let me know what numbers are on it and i'll check my inventory. they are cheap. greg I am sorry. I meant this for thetudor. frog

I have a 64 40hp eletromatic with a bug in the charging system. I can run the thing down so low that the battery cant start the motor and have to use the rope starter. but the lower unit will still drive the prop.so I dont think that low voltage is the problem. I have seen a guy tare apart a good 62 40hp lower unit and sell the motor cheep. thinking that it was junk. all that was wrong was the prop was bad.so iam thinking bad prop. Bob

small possibility that it is a worn clutch dog........

Electric shift has no clutch dogs.

I agree with ED-MC 100%

It is possible for the spring to hub interface to slip but very rare.
Be sure to use the correct oil (premium blend/type C).

I also agree with Ed. My 75 hp electric shift did the very same thing years back. It was the rubber bushing in the hub of my prop.

I had the rare occurrence of one kicking out of gear at medium to top speed and then jumping back in gear on our 64 Johnson 40. Definitely wasn't the prop as I've had enough experience w/ bad hubs. This one would go back into gear like you just shifted it. I was soured on them ever since. The local guru mechanic also told me they were mostly trouble free though.

When they kick out of gear due to bad clutch/gear, it feels like someone is hitting the transom with a mallet when the gearbox re-engages. Usually does lots of damage to the gear as well as the clutch, and if both aren't replaced the remaining bad part will likely take out the new part.

A slipping prop hub allows the engine to rev up freely and that's the best way to tell the diff between bad parts in the L/U and a slipping prop.