Finish writing Thesis or continue research

I would like you to give me some advice about the next step in my work as a PhD student.

Right now, I should choose between writing Thesis or continue doing some additional research. These research tasks are about genetics, the first one, and metagenomics, the second one. The first one is not funded, the second one is. They are related to the same bacterial specie I've been working but I cannot include the in Thesis since are not tightly related.

All three tasks are long tasks (more that 1 moth to finish) and hopefully less than 2 months. All them have a deadline, when the PhD scholarship finishes in August!. All three tasks will start with a 1 week reading phase. Thesis finishing involves only writing, while the other two tasks involve also running programs.

I think I should write Thesis and finish this task, then do more research.

Thanks