Engines turn over slow or barely . Won' start without jumping it with another battery . New batt

It may be new but it sounds like it does not have a full charge. Have you charged this battery or temporarily swapped it out?

Batt charged / replaced / grounds checked /solinoid bypassed /

Batt charged / replaced / grounds checked /solinoid bypassed /

How many volts do you read off this battery and how many off the one used to jump? Also check your oil level to be sure it is not over filled

Which engine does this have in it?