Loose sho prop nut

[Hchamberlin1]

I just had my boat in for its 20 hr service. Upon picking up and fishing another few days I noticed that the prop but was only hand tight at best. It had the new cotter pin in it but the nut would turn left or right against the pin. Obviously knew that was wrong and torqued it to 40 lb and put the pin back in. But why would a dealer purposefully set the nut at that spec. It’s not like it loosened up because the pin was fine. Everything looks good and the prop looks fine still but I’m just curious if some do it that way. I would like that a quick slam could snap that pin right off

[bandit53]

I have been told to tighten the prop nut to 90-90 lbs. When tighten to only 40 lbs or so, with time the thrust washer begins to seat further "back" on the shaft, resulting in slack without the prop nut having moved.

[Hchamberlin1]

That does make sense in theory how that could happen. Luckily I caught it before any damage was done. Thrust washer is good still but you can tell the one side is shinier than the other from not being tight. I torqued it to 50 lb now then another 1/8 inch to get the pin in

[Hooked247]

Straight out of the manual: Propeller nut 54 Nm (5.51 kgf-m, 39.8 ft-lb). Put in cotter pin, and your good.

[bgibson]

crank it down and be good with it.

[CJ1]

Their prop torque spec is about like the break in instructions. It would work in a perfect world but we don't live in one. Tighten the dang thing. I use 75 or a bit more to get the key in and only have had one loosen on anold suzuki with the wrong backer washer. Cj

[TBagn]

Keep an eye on it. I thought the same thing when i did a walk around of my motor after a day on the lake. With only 13hrs on the motor, i realized my prop nut was a little loose. When i took it home, i pulled the whole prop off and realized i had severe damage to my lower unit. Took it by the Dealer and without getting into to much detail, the dealer said warranty will cover it and that they have had a few like this in the last year or so.

When i asked the dealer what was the issue, they stated that it was a "prop failure" () due to the Hub not being seated well enough from the factory. After about a weak, i had a new lower unit and a new prop.

FYI, A buddy of mine has had the same thing happen to his (he's 750 miles from me, so different dealer, along with different make of boat as well). His motor is a 2018 and he noticed it at 26hrs. Mine was a 2019 and i noticed it at 13hrs.

[TBagn]

[Hchamberlin1]

Wow that’s crazy. I would say I got lucky that I seen it because it wasn’t even hand tight. I pulled it all apart and luckily found no damage like that. I saw a few shiny pieces on the thrust washer but no visible damage. I’ll definitely be checking the torque spec every 5-8 hours for a while

[TBagn]

Well, Yamaha knows that this is an issue. Both my buddy and i got the issue taken care of with no questions ask. If it comes loose again, i would say take it by the dealer or run the shit out of it to make it look like mine. You'll get a new lower and a prop out of it.

[bgibson]

Like I said before, why don't you just crank it down and be done with it?

[Hchamberlin1]

It is indeed cranked down now. I checked it again today and although it hasn’t moved, I cranked it to the next hole. About 80 ft lbs on the torque wrench. To me, 40 was way to loose