Motoscrubs.com

Maybe everyone by me knew this but I thought I should share a recent solution to an oil leak problem I have had. Since restoring the bike, there has been a leak from the final drive shaft where it exits the case no matter how high or low I fill the oil relative to the marks on the dipstick. While installing one of Lacey's clutch push rod seal kits I also changed out the drive sprocket to the one that Lacey sells with the correct reverse thread on the engine side of the sprocket. This solved my oil leak problem immediately. I thought I should share my experience as I bought the one that caused the leak from a prominent seller of Ducati bits and upon inspection, I realized it had no scrolling on the engine side of the sprocket at all. I guess I never caught it as I was assembling the bike, so lesson learned.

I bought a sprocket from a "prominent" dealer as well. Mine had no spiral and on top of that the boss was under size as well.
Big time leaker. I took that one and turned a brass sleeve on my lathe, press fit it in place and turned to the proper diameter WITH the correct rotation oil groove. Again problem solved. They are supposed to look like the attached picture.

Mike Mc

Brilliant solution Mike. I need to buy a small lathe. It is the one major tool I do not have. Your picture is exactly like what I installed as well.

Good information! Thanks for the heads up. Have been thinking about getting another 17 or 18 T sprocket. Will be on the lookout for the problem sprockets.