was fine a few weeks ago, but seems when starting it is turning over slower. 2 new batteries, starter contacts done within the last year and a half.

when running, guage shows normal for charging, but no i have not confrimed with a meter. could anything else be drawing when i go to start?

 

Dirty battery connections

 

That and starter brushes - contacts are only 30% of the solution - also check the cables\posts for corrosion\oxidation

 

Electrically the most likely culprits are corroded connections(sometimes the whole cable needs replacement) or the starter brushes.

Is the slower cranking speed that you are experiencing a function of the temperature? 15w40 oil is really thick at colder temps which is why so many people use a thinner synthetic.