Stator Grommet Solution?

[The1970's]

After finally getting my bike dialed in I've turned my attention to the small yet inumerable oil leaks. I have now replaced the gaskets for the breather, valve cover and oil pan. What I originally thought was the oil pan gasket leaking I am now thinking is the starter O-ring. So I planned to put a new o-ring and also re-seal the timing chain tensioner and oil pressure sending unit while i'm in there. Anyway, tonight I pulled the starter off and to my surprise found absolutely nothing resembling a grommet on the stator wiring. In comparison, the area around the wire seems to be relatively dry but I know there is supposed to be something there.

My question is if anyone has come up with a solution for sealing the wire that doesn't involve buying a new OEM stator? My all original charging system is still functioning well and while I did plan to upgrade, i'm not quite ready to spend the $260 for a new stator.

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[The1970's]

Here's another shot so you can see all the leaks, it looks like some oil may have also been making its way in from the sending unit as well:

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[Sasquatch]

Mine didn’t have a grommet ether. I looked at parts diagrams and didn’t see one. There is drain holes on the sump make sure they are clean.🏍

[GregT]

It doesn't have a grommet there. The hole you can see leads into a blind space in the outer cover. The grommet is actually on an internal wall of the outer cover.
If you pull the cover, you'll see it.
That hole is as big as it needs to be to pass the stator wiring harness plug through when the outer cover is removed.
What's in the starter motor recess has come from the starter motor O ring area IMO. Pretty normal.

[Steve]

Yet another confirmation that there is no grommet there, but also have to ask: where are you shopping that a stator is $260? I want to be SURE to avoid that place. Most of the better-quality stators available are about half that amount.

Back to the oil issue: the main gasket around the stator is the half-moon where the three wires pass from the stator cavity to the starter idler gear area. IF that is compromised, you will have oil build up around the idler gears. If you have enough oil there, it might be possible to get past the o-ring around the nose of the starter, where it pokes into the idler gear area. The amount of oil you show does not indicate a leak in either area.

In your second picture, I see something black sneaking into the corner of the starter cavity directly behind the cylinders. Can't tell if that is the starter wire or a vent hose. Not sure if your bike has a vent hose, but my shaft-driven bikes do. The vent empties into the starter cavity as a semi-protected area, and there is a large drain hole (also known as "the mystery hole") below the starter. It empties out the middle of the drain pan, which could easily lead you to think you have an oil pan leak.

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[chuck hahn]

I use a bit of carb spray to clean the grommet and then apply some Ultra Black RTV around the wires and massage it in. Then a nice amount around the grommet as well and install the unit.

[The1970's]

Yet another confirmation that there is no grommet there, but also have to ask: where are you shopping that a stator is $260? I want to be SURE to avoid that place. Most of the better-quality stators available are about half that amount.

Back to the oil issue: the main gasket around the stator is the half-moon where the three wires pass from the stator cavity to the starter idler gear area. IF that is compromised, you will have oil build up around the idler gears. If you have enough oil there, it might be possible to get past the o-ring around the nose of the starter, where it pokes into the idler gear area. The amount of oil you show does not indicate a leak in either area.

In your second picture, I see something black sneaking into the corner of the starter cavity directly behind the cylinders. Can't tell if that is the starter wire or a vent hose. Not sure if your bike has a vent hose, but my shaft-driven bikes do. The vent empties into the starter cavity as a semi-protected area, and there is a large drain hole (also known as "the mystery hole") below the starter. It empties out the middle of the drain pan, which could easily lead you to think you have an oil pan leak.

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Thanks everyone for the heads up that the grommet goes in the cover itself. I guess there is no issue with mine. As for the price of the stator parts outlaw lists the generator assembly at $252.62 im sure it could be had cheaper but I just took a quick look while ordering some misc gaskets.

That wire you see in the corner is the lead that goes to the oil pressure sending unit just under the cam chain tensioner.

If I read your comment correct it would seem the starter O-ring is a "Secondary" seal as there really shouldn't be much oil in the starter gear area in the first place, correct? I think I had mistakenly identified the oil pan gasket leaking. Now I have oil covering the left hand side of the oil pan and it appears to be originating under the sprocket cover on that side. The shift shaft seal and Gear indicator switch are not leaking so that led me to believe the starter O-ring. I'm just going to replace that and the tensioner gasket and go from there

[Steve]

Thanks everyone for the heads up that the grommet goes in the cover itself. I guess there is no issue with mine. As for the price of the stator parts outlaw lists the generator assembly at $252.62 im sure it could be had cheaper but I just took a quick look while ordering some misc gaskets.

Although Parts Outlaw is a favorite of many of us here, I guess nobody has thought of getting an OEM stator.

The fact that you have a 12-pole stator make is a bit harder to find, but they are available.
Electrosport. for $119
Electrosport stator from Amazon for $82.52.
Electrosport stator on eBay for $87.21.

Interesting to note that they are all Electrosport stators (yes, even the same part number). Most of us here agree that it is probably one of the better stators available.

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[bwringer]

Much of the oil you find in the cavity under the starter on a GS is from a leaking cam chain tensioner.

Don't just replace the gasket for the cam chain tensioner -- replace the seal and o-rings.

Here are complete instructions with part numbers and everything:

http://www.bwringer.com/gs/camchaintens.html

[chuck hahn]

How will the tensioner leak into the starter well?? I can see the oring at the end of the starter motor weeping oil past it though.

[bwringer]

How will the tensioner leak into the starter well?? I can see the oring at the end of the starter motor weeping oil past it though.

It's both. Volume-wise, a starter motor o-ring can probably leak more oil than a leaky cam chain tensioner seal.

There's a slot in the wall of the starter cavity where the starter cable exits. Oil drips from the seal on the cam chain tensioner onto the engine, then runs into the starter cavity and out the Mystery Hole. I've also seen the oil pressure switch leaking, but that isn't common.


The slot in this pic of an old GS850 engine is at the bottom left of the upper orange circle.


Here's the outlet of the Mystery Hole. The blue tubing is only there to show they're connected.


Basically, any fluids on top of the engine will make their way into the starter cavity and out the Mystery Hole.

[The1970's]

Don't just replace the gasket for the cam chain tensioner -- replace the seal and o-rings.

Here are complete instructions with part numbers and everything:
http://www.bwringer.com/gs/camchaintens.html

Yep I can see a portion of my leaking oil is coming from the tensioner and pouring into the starter cavity right where the oil pressure sending unit wire comes through.

About the tensioner rebuild though: I only saw the base gasket and 1 O-ring on the parts outlaw site. Does my 78 GS750 have a different tensioner than your 850? Or is there somewhere else to get the seal and other O-ring from?

Edit: Now that I actually read the top of your site it makes sense

[chuck hahn]

Isnt that slot the one the oil switch wire passes into and isnt it also encased in a rubber grommet that slips into said slot...if my memory serves me correctly?? In which case a leaky tensioner gasket shouldnt get oil into the starter well??? Im not out looking at any of my bikes right now but I will in the morning now.

If so, then a little swipe of RTV there should eliminate any leakage too.

[bwringer]

No, there's no grommet on that slot. The starter wire passes through there, and depending on the bike, a few other wires and tubes. Water and whatnot drain through the slot, into the bottom of the starter cavity, into an empty space between the crankcase castings, and out the Mystery Hole. This is right, normal, good, and by design so the starter doesn't drown.

I started calling it the Mystery Hole a while back because we would regularly see posts from people who were tracking an oil leak or just generally rummaging around in the seldom-seen areas underneath their engine, and would FREAK OUT because OMFGWTFBBQ THERE'S A HOLE IN THE ENGINE!?!?!?!?!??!!!???

I recall more than one person who sealed the Mystery Hole with epoxy, and several who had to be stopped from doing this. If the Mystery Hole is sealed up, the starter cavity will fill up with oily water the first time you ride or park in the rain. And you can imagine how marinating the starter only leads to heartache and angst.

If oil is coming out the Mystery Hole, it's the o-ring on the nose of the starter and/or oil from a leaky cam chain tensioner.

You can also get oil in the neighborhood of the Mystery Hole from a leaking o-ring around the gear position switch.