1978 25hp Evinrude Problem

Guys I had this motor on the lake about 3 weeks ago before I converted it to electric start. I pulled it several times choke on before it hit, then a few more times before it fired off and ran. Ive had several of these 25s lately and this one seemed to have a funny feel to it while pulling the rope- almost like trying to pull start it in gear......just a sluggish slowwwwwwww feel to rope. It did however fire up and ran well in a all day fishing trip and ran surprising smooth at idle. Yesterday I converted it to electric start and upon getting everything tightened and wired up I thought I would spin it over a few times dry just to check my work. It would turn over but seemingly at about half the speed it should have. The battery is brand new and fresh charged and I even swapped the starter for a known good one I had stashed away. this thing should really spin fast but same result.....very slow turnover. I havent tried it yet in the tank but it seems to me that its not even turning fast enough to start ? It sure has me baffled as I know it ran and ran good a few weeks ago albeit the strange feel to the rope........any ideas at all? BTW the motor had set up a good while before I got it running. And it was a Florida motor so I assume it has seen some salt water usage........Any help appreciated thanks

Pull the spark plugs & see if that makes any difference.

I figured it out finally. I was trying to use a factory OMC stop switch as a starter switch. It wouldnt pass enough amperage to give the starter full current. I bypassed the switch and it whirs and purrs . Now to find a dedicated starter button and Ill be in business. Thanks.