start or started and others please help me.

  1. He couldn’t make his motorbike start/ started this morning.

  2. Always to be/ be honest in whatever you do.

  3. Is he looking for his key at the moment? Yes, he lost it 3 days ago.

be honest

I have gotten the key is " start" and “be” but I don’t known the reason why. I read some books I saw the structure " make something + V (past participle) so in my mind I always thinks it is “started” but the key is " start"

and the second one I really don’t know why it is but not “to be” please help me.