Oil in starter motor

[ScavengerProd]

So.. I seem to get oil in the starter motor. Anyone encountered this?

Couple of years ago I did a silly and put too much oil in the engine, and the increased oil-pressure escaped into the the starter (I theorise). I had a wonderful time cleaning out the oil-and-carbon-gunk and bought an overhaul kit and re-did the engine oil. However, it has turned into a recurring issue, and I can't seem to figure out the fault. I've had a look at the crankcase breather and it's perfectly clean and I can't see any other signs of too much oil pressure. Engine runs fine.

My thoughts are maybe bad rebuild kits or that I re-assembled the starter wrong somehow. Any experiences or thoughts? Anyone have any pictures of their disassembled starter and the order of parts on the side towards the engine? I'm thinking maybe that the gasket doesn't sit snug enough. Just to specify, the oil leaks into the starter, and does not escape out around the sides.

BR,
Konrad

[FJmonkey]

The starter (and alternator) has an internal O-ring that can fail and cause this kind of leak.

[FJ_Hooligan]

A bad o-ring will leak oil onto the engine case.

Sounds like a bad seal on the output shaft of the starter, maybe?

[ScavengerProd]

Thanks. It's the gasket by the bearing towards the engine I think to be the culprit too. The thing is, I have exchanged this part several times now and I'm not sure what I'm doing wrong. How snug is the gasket supposed to be? It might be that the repair kits I've used are bad, or that I have done assembly wrong. I love my Haynes manual, but it doesn't show me the order of the internal parts of the starter. Any special install procedure I'm not aware of?

[Old Rider]

Since i just have done some fixing on my starter i tok it apart and did some picks.First my guess was that the bike had ben laying on the left side or doing wheelies,but when opened starter again
i found the inside oil seal.Also you can se the order how the spacers is .I got one more spacer that on the partdiagram dont know why..

[ScavengerProd]

Since i just have done some fixing on my starter i tok it apart and did some picks.First my guess was that the bike had ben laying on the left side or doing wheelies,but when opened starter again
i found the inside oil seal.Also you can se the order how the spacers is .I got one more spacer that on the partdiagram dont know why..

Thank you so much for the pics. Although my starter is the 4-brush version, they should be similar enough for troubleshooting.

[FJ_Hooligan]

I don't see a call out for what is obviously an oil seal in the output shaft housing.  Installation of that seal indicates it's supposed to keep oil in the engine and out of the starter.

Measure it and get a replacement.

[ScavengerProd]

I don't see a call out for what is obviously an oil seal in the output shaft housing.  Installation of that seal indicates it's supposed to keep oil in the engine and out of the starter.

Measure it and get a replacement.

Issue is, I have replaced it two-three times now...

[FJ_Hooligan]

I hate to ask this, but are you installing it with the hollow lip side facing the engine side?

[ZOA NOM]

The pictures seem to show the correct orientation.

[racerrad8]

Issue is, I have replaced it two-three times now...

Which seal have you replaced?

Send the parts number or a picture with the location of the seal you have replaced.

Randy - RPM

[FJ_Hooligan]

The pictures seem to show the correct orientation.

That's not his picture

[ScavengerProd]

Yes, installing it with lip towards engine (if I have done this wrong by mishap three times now, I don't know what to say...).

I'll be able to get some pics of my own starter on Wednesday. And I've used a complete rebuild kit each time, so all gaskets replaced, with brushes and the like. I got sent 5 kits, not 1, by the store so lucky me! Anyone able to provide exact measurements of the gasket in question? Might be that the kit I have is useless. Needs to be 4-brush, late model.

EDIT:
So my theories are:
- I'm stupid: assembling something wrong
- I'm stupid: lost some piece, possibly a washer, so there's not enough pressure on the gasket
- Gasket is the wrong size
- Engine is about to blow

[ScavengerProd]

To put it simply, I think I found the fault... So, how do I get a gasket that fits? Reason for not catching this before is that I always put the gasket on the inner part of the starter and that fit snug.

I measured the insert, and gathered the gasket should be of 25mm outer dim, 15mm inner dim, 8mm height.