Sluggish starting

Hey everyone, I noticed my 2000 PSD EX is starting sluggish the last couple of days. Last time it sounded like this one of the batteries was no good, replaced it and everything was fine. that was a couple of years ago. So when I noticed it doing the same, i tested both batteries with a cca tester and the one I replaced 2 yrs ago was good, now it was the other one, so i bought a new battery today cleaned the K&N air filter and it still starts sluggish. The alternator and the starter have been replaced within the last year and half.
Any suggestions?
George