I have more problems with jock itch than athlete's foot after a long ride.  

Thanks for the info Dave.  I'm gonna go pick up a can of that foot powder.  That looks to be a great tool.  Glad you got that leak nailed down.  How many miles do you have on that flat-top now?

Dave, you definitely need to round out that tire wear issue!  Square tires are really bad!!  Enjoy your ride in the mountains!  Say Hello to MMRanch for me!

Hard to believe - but I am still chasing a bothersome oil leak.

I can take a short ride to town and back without any new oil spots - if I go for a 30 mile ride and get the bike really warm I will get 4 or 5 tiny oil spots on the tin shield behind the starter.

The oil leak on the right side is now gone - but I did have a bit of oil on the area behind the oil fill plug.  I had replaced the O-ring but it still had some oil weeping from that area.  I took out the plastic threaded cap and put in a metal one from an earlier bike - that appears to have stopped that leak.  This area never leaked prior to the oil pump overdrive gears.....perhaps the oil bypass jet that I installed on the backside of the oil filter housing has increased the amount of oil splashing up around the oil fill hole.

I got looking at the engine after a ride and the right side of the engine is clean - but I noticed the left side had a considerable amount of grime behind and under the pulley.  I removed the pulley cover and confirmed that the area was a mess - so I ordered a new output shaft O-ring and seal.

I took things apart last night and carefully inspected the parts as they were removed.  It did not appear that any oil was leaking out the seal on the outside of the pulley spacer - however the splined shaft was oily.  It appears the oil has been coming out the O-ring on the interior of the pulley spacer and then weeping out where the spacer and back of the pulley meet......as that had a thin coating of oil on it (there was no traces of oil on the front of the pulley).

I then took some mineral spirits and cleaned up the side of the engine.  When I removed the pulley spacer and wiped down the shaft I could see a thin line of brown deposits on the shaft where the O-ring had been sitting - it appeared to be rust!  I took some 800 grit sandpaper and removed the brown ring around the shaft, and installed the new O-ring and seal, and will put the rest back together today.

It appears this area has been weeping a small amount of oil for quite a while - but the amount of oil was small and not noticeable.  When I installed the oil pump overdrive gears and increased the oil pressure it appears the weep increased enough that oil on the backside of the pulley is becoming airborn when I get up to 50-60mph speeds (low speed rides to town evidently don't get enough air moving to blow the oil up behind the starter).  I will know in a few days if this will cure this elusive oil leak.

The photo is the area cleaned up prior to removing the pulley spacer and seal.....I had removed the seal retainer to allow me to clean up behind the spacer, and I put the screws back in to avoid getting dirty mineral spirits into the threads.  

ThumperPaul wrote on 09/12/24 at 05:33:53:


When I was young I worked with a fellow that had a drag car that was "T bucket" with a Hemi that would turn 9 second times in the quarter mile.  He offered to let me drive it once - I declined the offer.  A couple months later he was going down the track and a rod broke and he suddenly had 8 quarts of oil all over his tires and he made a few spins before he came to a stop!  I am "soooo" glad I didn't take his car for a "spin"!

Hey, throw us a bone will ya.  Howzabout lettin a little protective coating of dirt & grime build up before you post pics.  Jeeez that thing is clean.  My compliments.

I am surprised that you have a leak at that particular o-ring.  It's a static joint and the o-ring fits super-tight.  I was more concerned about the seal blowing out.  That's why I fabricated the special fitting so I could measure the pressure in that area.  As I recall, it was pretty darned low.  Any chance you are missing the o-ring on the orifice, or the orifice has been enlarged?

If that output shaft o-ring was leaking, you should have oil tracking all around the inner face of the pulley.  How did that face look?  Was the nut good & tight?

So the result of the change of the drive pulley seal and O-ring is that I may have reduced a bit of oil seep - but it did not cure the oil drips that occur on the top of the engine near the starter.....and it appears the source of the oil is still the top of the clutch cover where the pressurized oil galley is.

This is a couple of oil spots after a 30 mile ride.

Dave.  I’m probably wrong, but it “looks like” the oil is dripping down from somewhere above (but where would that be?).  I realize oil can get splashed around and blown from just about anywhere.  That head bolt that lives in the cave below the carb intake perhaps (but I’m sure you’ve checked that)?

The fact the leak didn’t start until you beefed up the oil pressure says something.  Gaskets and seals just can’t handle it?  

It’s ridiculous what they charge for the clutch side gasket.  Like you said, $30.   And it’s not even the good one with the metal inside.  The alternator side is still only $17ish.  I don’t get why the big difference and if I recall correctly, the clutch side gasket used to be like $17 just 6-7 months ago.

With that gasket not being terrific, it sucks the wallet has to take a $30 hit each time you pull the cover or risk a pesky leak.