'63 QD-24b Johnson 10HP Something is slipping while under power *FIXED*

[Fishy55]

Just had the clutch dog and gears welded and ground, thinking they were the cause, but the motor high revved again while in forward gear and under power. I can get up to about 3/4 throttle before something slips and the motor revs up high and I quit moving forward. If I back off the gas, it hooks up again. Is there any adjustment in the shifting linkage? Could something have been put onto the prop shaft backwards? So far, it's never slipped out of reverse. Thanks for any suggestions.

 

[jbjennings]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

MY suspicion is that your prop hub is slipping. You may think that your prop is a "pin-drive" and has no hub to slip---but it does.....
If it feels like you hit a stump and then it revs up, it is likely the clutch dog or a worn out shift connector under the powerhead. If it just gently starts to rev up, then it's the prop hub. You can make a mark across the prop and brass center hub and take the motor for a "spin". If the marks don't stay lined up--it's your prop hub.
Good luck,
JBJ

 

[Monte1961]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Agreed^

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

There's never any sort of 'bump' or noise, it just loses forward speed and revs. The newly welded clutch dog and gears show no sign of wear after their first trip on the water yesterday. That would rule out the need to adjust the shift lever, right? I was afraid that perhaps the clutch wasn't fully biting into the forward gear, but there should be wear to prove it, and there isn't. Can you help me out with this prop hub? Not sure exactly what you're talking about. I wish I had the book on this motor...

Thanks fellas

 

[tx1961whaler]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

The propeller is actually two pieces bonded together with a thin rubber "bushing" . The inner hub (the part that slides over the propshaft) and the outer prop (the thing with the blades on it) can slip relative to one another if the rubber bushing is worn out.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Gotcha. Well I'm actually hoping that's the problem, because my buddy and I can't think of anything else that would be slipping like that. I'll go check it out. Thanks for the info!

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

I had dad hold the flywheel while i tried to spin the prop by hand. It wouldn't budge. Guess I'll have to take the boat out and see if the lines still line up afterwards. I'm guessing there are a lot more forces at play with a motor that's actually running and motoring forward as opposed to two guys trying to turn a prop by hand.

 

[jbjennings]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

I'm pretty confident from your description that it is the hub. You can't tell if it's slipping by hand. You'll have to test it out like you planned. You can get them rehubbed, but if your prop has any bends in it, you may as well buy a new one. They're only about 80 bucks or less.
Good luck,
JBJ

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

I could use a new prop anyway. Anyone else have any suggestions if a new prop doesn't fix the issue?

 

[Daviet]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

By the way you are describing the problem, it is a prop hub slipping. Get your prop rehubbed or get another prop.

 

[samo_ott]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

I think spun hub also. And when they get really bad you can spin em by hand.

 

[samo_ott]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Here are some pics of what my spun prop looked like.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Thanks Steve, mine doesn't look nearly that bad. It's fairly intact and doesn't have nearly the corrosion or whatever. But, it looks original, white paint and all. I'm sure it's ugly inside if I were to take it apart. New prop it is. Hopefully y'all won't hear from me again after this, haha!! I assume Michigan Wheel makes a decent prop? Thanks to all who helped, forums are a wonderful tool

 

[Daviet]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Post back and let everyone know what fixed your problem, may help someone else.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Will do Daviet.

 

[kfa4303]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

If the new prop doesn't fix it, then you'll want to look at the clutch dog in the lower unit. they often wear out over time and cause the motor to slip out of gear when under load. If you're lucky only one side of the dog will be worn. If so, you can flip it around and use it a bit longer for your forward gear, however, you may find that reverse may slip instead. It's a trade off that you may have to take unless you're willing to buy a new clutch dog, which is about $65 for these old 10hp. keep us posted. Good luck.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

kfa4303, I've already had the clutch dog and gears welded back into shape. There is no wear on the 'biting' edges, so I'm assuming they're fine. The motor never lurches or clunks or bucks when it starts to rev up. It's all very fluid and smooth, so I'm siding with the prop hub slipping. It's funny, because I actually said out loud the very first time it happened, "It's like the prop is slipping!" I never actually knew it was possible, haha. I'd like a Solas prop, but I don't see a 8 1/4x 8 1/2 on their list. Probably going to order a Michigan Wheel, I found one for $67, $15 for shipping though...I'll keep y'all posted, thanks again.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Received my new prop today, Saturday is the big test. I'll report back on whether or not the new prop relieves the slipping I've been experiencing. Going to decarb the motor first, picked up a bottle of Seafoam tonight. Can you believe Wally World is getting $9 per bottle!?!? I'm Gonna say my prayers tonight that my outboard whoa's are over, at least for this summer...

 

[Monte1961]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Ok sounds good. But after your done running seafoam and you run fresh fuel mix, change your plugs out also. Post back results.

 

[Fishy55]

Re: '63 QD-24b Something is slipping while under power

Re: '63 QD-24b Something is slipping while under power

Took the boat out for a spin today and no more slipping!! The new prop appears to have solved the problem. I went with an 8 1/4 x 8 1/2. It seems a touch faster than the old one of the same size and pitch, which is good. Probably because it's in mint condition and isn't as 'seasoned' as the original, haha.

So, what I've learned is: If your motor smoothly starts to rev up while accelerating, and you're not being propelled forward, it's probably a slipping prop hub. If there's a clunk or any sort of 'roughness', it's probably your clutch dogs/gears going out or slipping. I'm very greatful for everyone's input on this. Saved me a lot of worrying and wondering, not to mention time and money. Hopefully this post helps someone else out. If your prop looks original, and it's on something as old as my 1963, it's probably in your best interest to replace it. It just might save your next weekend fishing trip.