Johnson 5 hp 2 stroke clutch slipping?

[Sy-Revolution]

I've just noticed a problem with my OB. Going along nicely and suddenly it's as if a clutch is slipping, engine revs up but traction goes. I've checked the shear pin etc and it's fine so it's not the prop. Do these things have a clutch? Is it likely to be a gearbox problem?

Any ideas?

Model No. J5REE 1999

Cheers,

C.

 

[VicS]

They have dog clutch. If they become worn ( due to gentle gear engagements ) they can jump out of gear. You can re-engage gear with the gear shift.


BUT that model has a rubber bushed prop. That can slip as you increase power but drive again when you reduce the power.
I suspect this is your problem

See http://www.boats.net/parts/search/BRP/JOHNSON/1999/J5REEC/GEARCASE/parts.html

 

[Sy-Revolution]

Thanks for your reply Vic, so is that a new prop needed do you think or is it a part inside the lower leg?

Cheers,

C.

 

[Lakesailor]

It's the prop.

 

[VicS]

Thanks for your reply Vic, so is that a new prop needed do you think or is it a part inside the lower leg?

Cheers,

C.

It's the prop hub bush part # 36 in the diagram. It's available as separate part but I dont know if you can press a new one in yourself. Id think you could improvise something

Maybe LS knows a little more.

You can check that it is a "spun hub" as they call it

Make a mark on the prop that lines up with say the head of the split pin (#38) through the prop retaining nut.
Go for a short spin.
If the mark no longer lines up it's the bush that has failed.

You'd know if it was the dog clutch because it would jump into neutral and you would have to actually re-engage gear to restore the drive.

 

[Sy-Revolution]

Thanks for that, I'll give it a try tomorrow.

C.

 

[KAL]

I had the same problem with a Yam 8 last year - the rubber bush on the prop went and the only solution was a new prop. Apparently, it's quite common.

 

[VicS]

I had the same problem with a Yam 8 last year - the rubber bush on the prop went and the only solution was a new prop. Apparently, it's quite common.

In this case the bush is avaialble as a replacement part.
A prop repairers should be able to fit it even if its not a DIY job

 

[KAL]

In this case the bush is avaialble as a replacement part.
A prop repairers should be able to fit it even if its not a DIY job

Hi Vic,
I wish I'd known this last year! The dealer assured me a repair wasn't possible, but I suppose he would do, wouldn't he...

 

[VicS]

Hi Vic,
I wish I'd known this last year! The dealer assured me a repair wasn't possible, but I suppose he would do, wouldn't he...

Dont know what model your Yamaha is but one picked at random does not list the bush as a replacement part.

 

[Lakesailor]

Iy seems that whilst the bush is replaceable, it is a bonding process.
This New Zealand site gives loads of info.

 

[Sy-Revolution]

Ok as, where we are now, there isn't a replacement/repair available I fashioned a workaround. Drilled and tapped an M5 hole through the aly prop, rubber bush and into the brass inner sleeve and bolted through, flush with the inner face. Job done...................for now.


Thanks for the information everyone!

Cheers,

C.

 

[jimmcgee]

see , last night I was going to post , how not drill a small hole through the side of the prop and put in a brass skrew to act as a sheer pin, just like I done with first 25 hp outboard lol.

 

[Sy-Revolution]

Ahhh, see I haven't drilled through the shaft, just the prop/rubber bush, inner sleeve. Orginal shear pin is still there, doing it's job.

C.