Prop nut

[HTHM]

When tightening a prop nut on a high horsepower motor, how tight does it need to be and are there any common mistakes made with the "tang" washer?

I am going to be experimenting with two props on the weekend and do not want to leave ~$450 on the river bottom...

[FisherMike]

hand tight with a cotter pin should do the trick. thats how we do it at the lodge i work at.

[Bernie]

Tighten it until the thread strips, then back it off a half turn.

 

Seriously though, on mine I set it to 80 lbft.

Take a couple extra cotter pins of the correct size, preferably stainless.

After a couple of bends I don't trust a cotter pin to stay in place, especially when dealing with the expense of a propeller.

[HTHM]

This prop shaft does not have a cotter pin hole that I have seen. It has a locking washer that has tangs on it that are bent back to lock it in place. The retaining nut is a nyloc nut as well.

[vinnimon]

Looking threw my manual(mercruiser)

The torque specs varies depending on what model gear housing you have.

It ranges from 18 ft/lbs to 55ft/lbs of torque.

Use stainless cotter pins and never, never reuse them if they are removed.

Call your lacal dealer for proper specs, and have the engines serial # handy.

[Terry]

just tighten it down

then line up 3 tabs and knock them into place

[morieris]

On my Mercury 75 4 stroke the torque is 55 lb/ft

[fishinguypat]

2 years ago when i got a new to me boat, i got out on the water and somehow the prop fell off, it turned out the pin was not attached so when we reversed it fell right off. I always check now

[Terry]

well now he know to check the pin

 

 

 

to bad he doesn't have one....

[Old Man]

55 ft lbs

[fish_fishburn]

My 175 EFI Merc shop manual says 80 lbs. I have had it on and off so many times over the years that now I just tighten really tight with a 1/2 drive rachet and never a problem. You must be able to bend at least 3 of the lock washer tangs upward to keep everything where its suppose to be. When you find the prop your going to keep, after a few times out bend the tabs down and snug the nut up again, bend the tangs back up and your good to go. Some marine greese on the spline is always a good thing as well.