[80cb400t]

Hello all, I noticed I had oil below the bike on the garage floor, turned out it was coming from the screw of the shaft at the bottom of the starter as shown below (not my starter but labelled in the same place).



Has anyone had this issue and know whether it's as simple as screwing the shaft out and replacing the o-ring (hopefully with minimal oil draining out)? Also to save me some guessing (from those of you who have been guessing long enough that it's not really a guess anymore), what size o-ring would this be?

Also this likely provides evidence for the case of not switching to synthetic on these bikes as I did not notice this leak before changing from black 2 year old mystery PO oil.

 

[76TWIN]

what bike exactly?

http://www.bikebandit.com/oem-parts/detail/honda/53438-611-000/b683356?m=151666&sch=17469

 

[80cb400t]

It's a 1980 CB400t hawk. The other issue is how do I get that screw undone without stripping it. Seems very fragile and my supposedly Japanese screwdriver seems to just be stripping it using the +1 head

 

[76TWIN]

Honda 91312-MG7-003 - O-RING (24.4X3.1) | eBay

for CB400T

 

[80cb400t]

I believe that's for the main shaft, looking at the parts diagrams there is no o-ring, just a 5mm washer on the starter motor cover bolt (which is no longer available). Can this leak even be fixed with a new washer? It seems to be torqued town extremely tight as well.

 

[76TWIN]

I guess I don't quite understand what you are referring to.
There should not be any oil inside the starter itself anyway so why would there be oil leaking at the bolt?

The only possible leak point would be from the o ring of the starter. Are you sure the leak isn't from somewhere else on the engine?

 

[80cb400t]

It doesn't make much sense to me either. Here's a picture of what the leak looks like on my bike.



It really seems to be leaking only from there but that does make sense about that being the only place. I'm going to take another look.

 

[76TWIN]

You sure the leak isn't from somewhere on top of the starter itself? It looks like it's dripping onto the starter and not leaking from there per se.

 

[80cb400t]

It's totally dry in the area between/below the headers and above the starter, there's some old oil behind the starter on the leaking side and the only place I can see fresh oil is that one screw.

I think I'll check again tomorrow, maybe something will jump out at me after a good sleep.

I think your first suggestion was correct, I bet if I removed the starter I'd find a very flat edged O-Ring.

 

[longdistancerider]

Most likely it's the starter O-ring that seals the starter to the case. If you're springing leaks suddenly then I'd take a look inside the left case cover at the starter pinion drive shaft O-ring, you can see the shaft ahead of the stator.

 

[80cb400t]

Well the leak has slowed down considerably, now just a small drop upon parking. I read somewhere that oil seals can sometimes dry out and shrink a bit, then expand again once they get re-saturated with oil. Maybe that is what has happened.

I'll probably take the starter off next oil change and replace that o-ring but I'll just check the oil often for now.

Thank you guys for the help!