Oil in Starter Motor!?!

Back to tinkering on the bike a little and getting her tuned up for better weather. I've been noticing its been getting harder and harder to crank the bike over.

Today all of that came to a halt when I got no go from the starter motor all the sudden. Thought it was the original solenoid, swapped and same thing. Direct power to the starter, nothing. So decided to pull it and bench test. Was able to get some life out of it but eventually tore it apart and well....I found my issue....



I have no idea how engine oil got in there but the internals are toast and for sure need another rebuild. Which when I first got this bike I performed a rebuild and maybe due to cheap parts? Really not sure.

Anyone else come across this issue before? Looks like I will order a legit kit from DB electrical this time.

 

The seal leaked behind the drive gear most likely, should come with rebuild kit.

 

Confirmed bad seal at the drive gear...

Did I put that seal in backwards?

 

nope , the "lip" faces the oil

 

That seal is installed correctly. One thing we have noticed in the variety of aftermarket rebuild kits out there for the 650-900 starter motors is that they come with an oil seal that is the wrong size....as in, either the complete wrong size, or, in the best case, one that is too thick. The original seal is 15-25-4.5 (15mm ID, 25mm OD, 4.5mm thick/tall .... which, as you might imagine, is an odd size for a seal) and we've seen kits with 15-25-6 (too tall by 1.5mm) or 14-24-6 seals (too small of an ID, too small of an OD, too tall.....what are they thinking?). Some kits comes with a 15-25-5 (5mm tall) seal, which will work (only a half-mm too tall), whereas others come with a 6mm thick seal, which although it will fit into the cavity (barely) , puts undue stress on the seal and causes it to pucker a bit, again leading to early failure.

One big "brand name" kit also comes with an incorrect sized bearing, and it's not even a ball bearing, it's a needle bearing.

 

Thanks Len!

Looks like it tore in 2 places which would cause the leak. I'll make sure to measure the new seal that comes in the kit I ordered

 

Okay, and the seal (like almost all oil seals) have their size cast into the rubber, so it will read as 15 - 25 - 6 (or whatever the size is); in most cases the dashes (hyphens) will not be present, and the spacing of the number around the circumference may be rather wide. In addition, there may be other random numbers, letters, or marks cast into the rubber, which can mean a variety of things, but none of importance in regards to the size info.

Of course, the kits we offer have the correct size seals included (bearing, too) or, if you already have a kit from someone else, we can sell you a correct size seal separate.

BTW, the seal you pull out of there will also have a size cast into the rubber, typically along the top face (where the "lips" are along the ID of the seal). Would be interesting to know what size it was.

 

The only identifiers on this seal are AGO585F 3 T

Measuring the seal I got the following - 15-25-4.15...

 

New kit came in, seal was stamped with 15-25-5 so it'll do just fine.



Put motor all back together and on the bike she went, fired right up. Let's hope I do not have to do this again for a long time