2003 Yamaha 50 hp problem

[armjr]

I have a 2003 50 hp 2-stroke Yamaha outboard. Today I was running at full throttle and lost power to the prop. At lower rpms the prop would engage and I was able to limp in to the ramp. If I tried to increase rpms the engine would run faster but the prop would quit turning. I have had no issues prior to this. The lower unit was warm to the touch when I got it out of the water. The water pump was pumping and the output stream was not overly hot.

Thanks for some direction on this issue.

Alan

 

[1988 Johnson 120]

With the engine off, put unit in gear and see if you can turn prop by hand.

 

[armjr]

Tried that. The engine turns over (naturally I have the key off). It appears that it turns with very little compression. But, there is nothing that sounds like it is broken or grinding when it turns.

Alan

 

[armjr]

The engine starts and runs fine, although the lower unit was hot (warm). It hasn't been hot like that before that I have noticed. The engine and drive works fine up to about 2500 rpm. If I go higher it immediately slips, the engine races and the prop slows down.

Is there a clutch inside the drive unit? I don't recall ever knowing or hearing about that.

Alan

 

[Propwash79]

How does it do in reverse?i would check to see if it spun the hub inside the prop. Dry the prop and use a paint pen to mark it and go run it and then check after it acts up and see if the marks are off. If that's good then check the foot pile for metal flakes or bits. If you find them them it's time for a rebuild or find a new foot.

 

[armjr]

Can I pull the prop and check it that way or is the part that's spun inside the unit? I really don't want to take it back out. I feel fortunate that I got in this time. I used up all my luck long ago.

Alan

 

[robert graham]

You have a "spun prop", caused by the failure of the rubber bushing between the inner and outer parts of the prop....fairly common...buy a new prop or have prop hub repaired by a prop shop, if available in your area...

 

[armjr]

It does fine in reverse but I do not run it nearly as fast in reverse as in forward, so I don't know if it slips or not. When it slips the engine winds out (till I quickly throttle back) and the prop stops turning, as if a clutch has slipped.

Alan

 

[99yam40]

Spun prop
slap another one on it and go from there.
If SS it would be cheaper to have it repaired than buying new

 

[armjr]

Thanks for all the replies. I'll pull the prop and do as suggested. It is SS so I'll get it rebuilt is possible. I appreciate you guys helping me out.

Alan

 

[armjr]

I have another question now. I will post it here and in the appropriate section of the forum.

My boat is an Xpress 1756 with a tunnel. I am primarily a freshwater fisherman but I do enjoy fishing the shallow bays. I pulled the boys skiing years ago but likely never will again with this boat. I'll likely get the prop that I have fixed and also buy a new one to either use or as a spare.

In the most extreme conditions (which are when I will be in the most danger of getting to camp on a mud flat in the middle of duck season or searing Texas sun) I need to be able to get up and moving in 2 feet of water (and mud) or less. I usually accomplish this by cutting the motor to one side, hitting the gas and going in a tight circle until I get some water moving in the tunnel and then I can go.

What would be your suggestions be as to the pitch of the new prop and a four blade as opposed to a three blade (like I have now)?

Thanks in advance.

Alan

 

[99yam40]

You will have to post what RPMs you get at WOT with the normal load you run, and what prop you are using now.
What is the HP rating of that boat?
A 50 on a 17+ boat and being tunnel you might be under powered to start out with