Doesn't sound like the oil leak could be in a really bad place; I'd be looking at the valve cover gasket and/or the plug in the back of the cylinder head. If you rule those out, could it possibly be coolant that is dragging some oil residue with it? Then check the Mikuni's small coolant line that heats the carb base (looks like a vacuum line), the heater hoses on the back of the engine and the intake manifold gasket. Keep the engine clean so it will be easier to detect leaks.

I have had big problems with starters. Once, I replaced mine with a rebuilt, lifetime warrantied unit and still had the same problems, so I thought the problem was elsewhere. It was right back to the starter again. Once I got another rebuilt/warrantied unit, all was well for a few more years - - just replaced it again this month after five full years (the last year, I had to occasionally smack it with a long wooden pole I carry), and the cost was once again nothing.

I am pretty good at removing and replacing the starter on the 2.6, as long as the bolts aren't too tight (like last time; Mighty Hercules put them in).

John B.