Xj650 seca engine rebuild

Hi all, i have an xj650 seca that i have been working on for the past year. I got it to work and rode for the summer. I found out that there is a oil leakage from the engine and would like to fix it myself as i did everything by myself on this bike. Is there anything i should pay specific attention? Is it just open, replace the gaskets and reassemble or would it be better to have this done professionally instead?
Thanks

 

Where exactly is the oil leaking from?
Typically the valve cover gasket is the culprit, this is easy to replace.
While you're there, optimal time to set the valves.

 

Thanks for your reply, I finally decided to disassemble the engine. I am afraid the culprit is the gasket between the cranck case and the cylinder. I will be replacing all gasket and hopefully that will take care of the oil leak. In the meantime I took a few pictures of the engine below and would like to get your feedback on whether you think I should be fixing / replacing someting else.

Also, in the process, I slighly damaged a couple of these small PINs Should I replace them?

Thanks

 

Is brake cleaner the best way to clean the pistons and cylinder head?

 

I use a plastic scraper to clean the pistons and a soft wire brush to clean the valves etc. Not tried brake clean.

 

Thanks!
Just the plastic scraper? No chemicals or whatsoever?

 

I don't use chemicals others might but that's what l do. Be careful some of that dirt from your engine doesn't get into your crankcases. I didn't bother because l was splitting the cases to do some repairs so it was easy to remove it.

 

The ChemDip for carbs works too