My son's favorite pastime at home is to build new maps for Halo, so when the literature teacher sent me an email that he was not putting forth his best effort, I let my son know that his time on X-Box would be directly tied to whether he brought his literature homework home for me to check. If he did an adequate job, he'd get more time on X-Box. If he "forgot" his homework at school or finished it at school and didn't bring it home, he'd have no time that day.
It's worked well. His work has improved dramatically and seemingly overnight.
So it might work for you to set aside 30 minutes that he needs to work on long-term projects that he hates to do. Once he's finished those 30 minutes and can show you what he's done, then he earns more time in Minecraft. Tie the things he hates to do to a reward that is valuable enough to suffer through it.
As adults, isn't that what we still do to get through things we don't want or like to do?
