TOPIC: Starflite: Copper Washers on Gearcase Head screws?

Oil was leaking around the gearcase head on my '66 Starflite 100. After removing the prop I can access the four screws that hold on the head.

The manual shows simply four screws, no washers, o-rings, etc, just screws. All four screws were loose, and on each screw was 1 small o-ring followed by 1 copper washer followed by 1 large o-ring.

Obviously someone's attempt to stop a leak, and I have to admit that it wasn't leaking around the screws, it was leaking around the perimeter of the head. But seems like there has be a cleaner way to deal with the screws that isn't prone to coming loose.

The screws are " fine threads "----should not come loose.

---

One o-ring to do the sealing.

---

There was never a problem with OMC motors that used those screws.

---

Even the later non electric used the same fastener set-up.

---

Strange that they missed showing the o-ring on the 100 HP , they do show an o-ring on the screw for the 40 HP ( same year ) electric shift.

They woke up on the parts book for the later STERN DRIVE ( same housing as the 100 HP outboard )

---

Show the screw 310412 and seal 307853

Single o-ring roughly the same diameter as the screw head? That would make sense.

The screws that you have should have a wee recess for the o-ring.

---

If not then somebody did something.

---

I pick these o-rings up from an o-ring supplier 20 cents each ( 50 at a time ) material is very thin if I remember.

Possibly a drop of "Loctite" on the screws would be acceptable? (Being an ex-Harley rider, I use that sh----stuff on everything!)

Closer inspection revealed the groove for the o-ring. One of them is pretty chewed up so I'll look into finding some new screws.

I'm a big fan of loctitie. When properly used it's a lifesaver.

Go dowh to horbor fright and you can get a whole box of differnt Orings for about 10 bucks.
Mike aks pathfinderz1

These 0-rings are very small diameter material not commonly found in a " kit "

---

best to go original here as there are many compounds of rubber / synthetics that can be used to make o-rings

---

It is not " all the same "

I've run into a few parts books that omitted the o-rings. And, if memory serves me correctly, the new screws come with the o-rings installed.

As for sealant, OMC and Mercury have a sealant that is great. I believe the OMC name is Perfect Seal. Maybe I have it backwares & that is Merc's name. Regardless, they are essentially the same stuff. Comes in a can (maye 16 ounces or so) with a brush. Cost is about $20. Lasts a longggggggg time. We don't use 1 can/year at the shop.

I use it on most evertything including cars & ATVs. I coat the outer diameter of seals too before I drive them into the housing. In regards to the lower unit screws, put some on all the threads & then screw them in. Will keep corrosion out of the threads too. Don't use loctite on those gearcase screws.

Update... the OMC name is "gasket sealing compound" and comes in spray p/n 771093, 4 oz can p/n 508235 and 16 oz cans p/n 317201.

The Merc product is p/n 92-34227q02.