Some issues came along like battery and it starts hard and I don't know why

I did change the battery and the after 2 years it runs out like from the + came some sulf

I did my carburetors clean and synchronized
I did change the sparks
I did my compression and by the tell of my mechanic its all good
I did clean the connector under the rubber of my starter
I don't know where to go
Any ideas are wellcomed