Just picked up 82 SECA 750 have ?s

Just picked it up has a repaint but is super clean with 20k miles, saw these can have starter clutch issues how common is that. And is syn or conv oil best for this

 

Nice machine. You should use only JASO rated oil for wet clutches and in my experience starter clutch issues have not been a problem for me. However the hub can crack although its not often it happens. The XJ machines have the starter clutch inside the crankcase so cases need to be split to replace it. Incorrect oil can cause the starter clutch rollers to skip on the alternator shaft another reason to only use the aforementioned type of oil.

 

That is a nice clean looking Seca 750. Congrats.

The starter clutch issues are a real thing, but I wouldn't be too concerned about it until it actually becomes a problem.

That being said, as @Franz mentioned, using the right oil can keep you out of trouble.

I will tell anyone who will listen that the best oil to use in these bikes is Shell Rotella T4 15W-40. It is JASO rated, readily available, inexpensive, and have never heard of an oil-related problem with it.

If you really want a synthetic, I would say go Shell Rotella T6 15W-40. It is also JASO rated, pretty readily available, and not too expensive. I am currently running it in one of my XJs that has a dying starter clutch - wanted to see if it would make it any worse, so far the answer is no. https://www.xjbikes.com/forums/threads/shell-rotella-t6-15w-40-synthetic-oil-experiment.132471/

Also check out:
https://www.xjbikes.com/forums/threads/choosing-the-correct-oil-for-a-wet-clutch-motorcycle.43702/

And:
https://www.xjbikes.com/forums/thre...building-your-slipping-starter-clutch.130438/