Have run out of things to try with prop nut backing off !!!!

[dls]

Have you tried some removable loctite just a thought but seems a new unlock would stay

No that's one thing I haven't tried yet. I'm been asking locals with Merc's if their nuts are backing off. So far I haven't found anyone that has ever even had their prop off. So they are no help either but they are quick to tell me their nut doesn't back off.

[2dwoods]

I've had mine off several times and I do check it for lose about every time I'm leaving the house because my 2 stroke has been loose before but I haven't found it loose yet on the 4 stroke and torque to 55 I'm running a bravo

[Another Distraction]

I'll help you collect data on this issue and hopefully others will too. It only takes 2 minutes.

I'll torque the prop nut to 55, mark it with a sharpie, and report back.

[Bass_boat_boy]

If it helps I don't have an issue and last season I was testing props and must have swapped out 3-4 with no issues.

[EuropeanAM]

Most of the newer HD hub kits contain the double-nut set now (1.25" shaft models).

Proper installation is as Pulseair2020 stated above: Thickest washer (first), thinnest (belleville) washer second, the then the mid-thickness. Install nut, pull down snug and then torque to 55 lbs/ft.

There would be no harm in torquing this to 65 lbs/ft, but even at the spec torque, the nut should not move in the short time span the OP says he was in gear. Shy of an explanation I would suggest trying a completely different hub kit.

The "double-nut" statement may be premature as pertains to the SSR kits. As of this moment, I believe that only the HD/Solid Hub Kit has received the Double Nuts. That is under Part# 8M0183487 (Service Bulletin 2022-19 covered this).

[Another Distraction]

DLS. How are you making out with the loose prop nut? Did you solve this issue?

I just installed a brand new Mercury brand hub kit to 60 FT- lbs, the belleville washer is in the correct orientation per instructions, and I used a lot of blue lock tite. I marked it and will let you know if it loosens up at all.

prop hub.jpg

[EuropeanAM]

DLS. How are you making out with the loose prop nut? Did you solve this issue?

I just installed a brand new Mercury brand hub kit to 60 FT- lbs, the belleville washer is in the correct orientation per instructions, and I used a lot of blue lock tite. I marked it and will let you know if it loosens up at all.

prop hub.jpg

You need to re-mark that nut to the SHAFT (not to the washer). Washers MAY possibly move under some circumstances.

[Another Distraction]

You're so right Don.

[sparkertx3]

The single big washer/double nut system shown in the photo is new, each nut is to be torqued to 85 ft-lbs.

https://community.brunswick.com/area.../article/16541

I got one a few days ago from my dealer when I whined about the pressed-in type hub.

[Another Distraction]

Where were you 3 weeks ago when I spent $145 on this crappy 710-8M0101603 one nut kit?! lol....

Your link says to still check the two nuts all the time and it says: "The new Prop Double Nut Kit (P/N 8M0179579)"

It also says it's for all "Mercury Racing outboard props" and you get it at a "Mercury racing" dealer. Is the double nut only for "R" motors?

[sparkertx3]

I have a 300R, but my dealer doesn't specialize in racing products. He had the part. I have it on a Fury, I'm sure it's good for all Mercury props. And yeah, they say to still check the torque frequently. But now you have two nuts to check and tighten.

[Another Distraction]

This is nuts....lol

[EuropeanAM]

This is nuts....lol

We gotz nuts on the shelf. 8M0179579