Gear slipping?

[chiefcatchemall]

Hey all I took my boat out yesterday and had a little bit of a problem. I have a 1965 evinrude sportwin 9.5 I was going wide open and then all of a sudden it felt like the gear slipped. I dont know if thats what it is though because it still pushes me but just slow. Other times I wont have a problem with it at all. And when it does happen its like it only lasts a minute then it will go back to normal again...Any ideas what might cause this?

 

[crxess]

Re: Gear slipping?

Prop slipping. Center bushing is shot.

Remove prop, make a mark from center to outer edge. Install and run boat duplication problem.

Remove prop and inspect line. if split into 2 lines prop needs rebuilt or replaced.

 

[chiefcatchemall]

Re: Gear slipping?

Alright thanks. Makes sense. Is it possible to just get the center bushing replaced or do I have to buy a whole new prop? Either way how much money am I looking at guys?

 

[crxess]

Re: Gear slipping?

If the blades are in good condition, repair should be reasonable.
Searching Google, http://www.propmd.com/ came up right off. Plenty of other places also do repairs.

A new prop will run $100-$150 The hard part is locating anyone that has one for the older motors. I know, my 9.5 is a '67.

 

[Home Cookin']

Re: Gear slipping?

I would think you have a shear pin, not bushing, on a prop that old. Usually when a shear pin fails, it's a total failure, but in my experience of going through about a bushel of shear pins, I did have one break but still catch the prop except at high speed.
If it's not the shear pin/bushing, it's the clutch dog, which may be pricey to fix unless you get lucky on the parts--maybe look for a seized-up motor to canabalize.

 

[chiefcatchemall]

Re: Gear slipping?

The sheer pin sits inside the slots of the center bushing. My question is, is if it is the bushing (which makes total sense) is there any way I could drill and tap a very small pin through the prop and the side of the bushing so that the bushing wouldnt slip anymore? Or is that just a bad idea?...

 

[crxess]

Re: Gear slipping?

That is a very bad idea.

And it is a Drive Pin - Not A shear Pin.

Prop Hub protects the gear case/prop shaft against strikes from Rocks and bottoming. Also absorbs shock from shifting and minor vibration.

Pin failure is supposed to be last line of defense from Heavy impact.

 

[lindy46]

Re: Gear slipping?

Alright thanks. Makes sense. Is it possible to just get the center bushing replaced or do I have to buy a whole new prop? Either way how much money am I looking at guys?

You can get the prop re-hubbed for $35-40.

 

[chiefcatchemall]

Re: Gear slipping?

Does that mean the bushing wont slip lindy? I dont know anything about outboards. This is my first one I have owned seeming how I am only 19. Just trying to get a better understanding of things...

 

[crxess]

Re: Gear slipping?

Getting the prop re-hubbed means your fixed. Back to the water.

 

[Home Cookin']

Re: Gear slipping?

I haven't run an old OMC for while but I didn't recall the props having a bushing at all; we just had the shear pins. So I pulled out a new-in-box Michigan my dad bought as a spare for our 1964 18 Seahorse back in the day. No bushing (rubber inside); just metal to metal.
Other small props I have on newer motors, and the big ones, have the rubber and they don't have shear pins, a shear pin groove or a hole in the shaft for one.
So Chief, when you pull your prop you'll see if you have a shear pin and you need to carry spares (and a cotter pin). If you mark the prop as suggested, duplicate the problem and the mark is off-line, you know you have a bushing.

At the prop store they might have a used/rebuilt you could buy for a spare; compare the cost to just a repair.

 

[lindy46]

Re: Gear slipping?

I haven't run an old OMC for while but I didn't recall the props having a bushing at all; we just had the shear pins. So I pulled out a new-in-box Michigan my dad bought as a spare for our 1964 18 Seahorse back in the day. No bushing (rubber inside); just metal to metal.
Other small props I have on newer motors, and the big ones, have the rubber and they don't have shear pins, a shear pin groove or a hole in the shaft for one.
So Chief, when you pull your prop you'll see if you have a shear pin and you need to carry spares (and a cotter pin). If you mark the prop as suggested, duplicate the problem and the mark is off-line, you know you have a bushing.

At the prop store they might have a used/rebuilt you could buy for a spare; compare the cost to just a repair.

The rubber bushing is inside but not visible. The hub looks like it's in direct contact with the prop, but the bushing IS in there.

 

[asdasc]

Re: Gear slipping?

The rubber bushing is inside but not visible. The hub looks like it's in direct contact with the prop, but the bushing IS in there.

Agreed! It is not visible, but it is in there, doing it's job, protecting you from evil.

 

[Home Cookin']

Re: Gear slipping?

Ok thanks--I'm here to learn, too.