Last year, I posted a thread asking if anyone could tell me what size bolt the propeller retaining bolt on the ETec V6 engines were and what the thread pitch was.
http://forums.iboats.com/forum/engin...e-for-etec-150
As you can see, I didn't get much help.
After doing some research I found out that it's a 3/4" shaft and fine thread (16 threads/inch) pitch.
The reason I wanted to know was that I am not a fan of the ordinary hex nut/flimsy castellated "keeper" prop nut combo that they are now using. I think it's cheap and unreliable compared to a proper brass castle nut like they used to use in the past. Well, I eventually lost one of those flimsy stainless steel "keeper" dealies and decided I was not going to replace it with another one and would get a proper brass castle nut instead so I started doing some research. Here is what I found out:
From 1976 - to 1986, OMC used to use proper brass castle prop nuts (PN 320569) and then they changed to the nut and keeper assy (PN 398042) in 1987 and still use it today on the V6 ETecs. They also used the 320569 castle nuts on the larger OMC stern drives from '78 - '86. I think they went to the 398042 nut and keeper cost as a cost saving measure only.
The old 320569 brass castle nuts are a direct swap for the 398042 prop nut and keepers. I know this because I now have one on my 2010 ETec 150 HO and it works perfectly.
If you have a post '86 V6 OMC/BRP outboard motor and agree that the new-style prop nut and keeper assy is inferior to the earlier castle nuts they used to use, you can still find some NOS 320569 brass castle nuts and used ones out there at pretty low prices but they are getting fewer and further between and some places that still have them only have one or two left in stock so if you want one, I suggest you hunt one and maybe a spare down and buy them sooner rather than later. I already have mine and a few spares so I am all set.
I know not everyone will see a need to change back from the 398042 prop nut and keepers back to the 320569 brass castle nuts but for those who do agree the newer system is not as good, I hope you will find this information useful.
http://forums.iboats.com/forum/engin...e-for-etec-150
As you can see, I didn't get much help.
After doing some research I found out that it's a 3/4" shaft and fine thread (16 threads/inch) pitch.
The reason I wanted to know was that I am not a fan of the ordinary hex nut/flimsy castellated "keeper" prop nut combo that they are now using. I think it's cheap and unreliable compared to a proper brass castle nut like they used to use in the past. Well, I eventually lost one of those flimsy stainless steel "keeper" dealies and decided I was not going to replace it with another one and would get a proper brass castle nut instead so I started doing some research. Here is what I found out:
From 1976 - to 1986, OMC used to use proper brass castle prop nuts (PN 320569) and then they changed to the nut and keeper assy (PN 398042) in 1987 and still use it today on the V6 ETecs. They also used the 320569 castle nuts on the larger OMC stern drives from '78 - '86. I think they went to the 398042 nut and keeper cost as a cost saving measure only.
The old 320569 brass castle nuts are a direct swap for the 398042 prop nut and keepers. I know this because I now have one on my 2010 ETec 150 HO and it works perfectly.
If you have a post '86 V6 OMC/BRP outboard motor and agree that the new-style prop nut and keeper assy is inferior to the earlier castle nuts they used to use, you can still find some NOS 320569 brass castle nuts and used ones out there at pretty low prices but they are getting fewer and further between and some places that still have them only have one or two left in stock so if you want one, I suggest you hunt one and maybe a spare down and buy them sooner rather than later. I already have mine and a few spares so I am all set.
I know not everyone will see a need to change back from the 398042 prop nut and keepers back to the 320569 brass castle nuts but for those who do agree the newer system is not as good, I hope you will find this information useful.
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