Starter Click before starting

My 1995 GT40 Pro Boss equipped Ski Nautique has started to click when I hit the key to start. Battery is at full voltage, connections are clean and when it does turn over it does so with full power and spins fast.
Sometimes I hit the key 3-4 times before it actually starts to spin the engine.
The other times it just clicks which indicates the solenoid is doing its job???
Some days it starts normally every time.
It may be rusty contacts in the starter itself. I did remove and clean the starter connections, they are clean and good.
Have not yet hit it with a hammer to shake rust loose.
This is not the neutral safety switch acting up because you hear the audible click each time the starter is engaged.
For me, it is not a big deal, but when someone else drives I have to explain the possible start delay.
I should share that while building a new engine for my nephews Jeep 3 years ago I had to put this boat outside in Winter for a couple months and my cover leaked. There was moisture inside but I only remember a couple inches in the bilge, starter not underwater but I am sure this contributed to the current issue.

Just curious what those with more electrical experience think before I tackle this.

Thanks
Mark

Thanks Ken, I am better with GM but have never been strong on electrical although I have been forced to work on more than I wish.
I appreciate the tips on checking this Ford.   We have a 5 day ski trip planned starting the end of this week so I better get on it.
I'll keey you guys posted.
Mark

Thanks Pete, I will make time to check it out today and I appreciate the tips.
I am hoping it will be a quick fix.

Pics of the removed starter, it looks to me like the lower starter bolt was never tightened from the factory based on the paint still not marred up from a bolt tightening.
The upper bolt was tight coming out but you can see the housing is marked from what I assume is movement due to the loose lower bolt.
But did this cause the click rather than start issue.

Mark,
Any signs of arcing between the starter frame and bell housing?

MrMcD wrote:    The lower bolt is very hard to get fully tight. I was only getting about 1 click of movement with my 3/8 ratchet due to space issues but it is now tight. Mark

If you use enough extensions hooked together to get the ratchet out in front of the front engine mount you can get a lot more ratchet movement and leverage on that bottom bolt

MrMcD wrote: I am really starting to like that tool, but it is only good for maybe 20 lbs of torque.

Whos brand did you buy?

Great to hear!

The tight threads could be from arcing over time, moving metal around little bit at a time

Pete, I had to go back and correct Milwaukee, I spelled it wrong. Did not mean to tick off any locals!

Ken, your note on the extensions had me thinking so I went back in and with 3' of 3/8 extensions, every one I own, I got on the 9/16" starter bolt again.
I got another 1/8" turn on it and feel better that it is tight.
The extensions allowed a much better position to tighten the rear bolt but with the blower motor in place I had to get on that bolt blind, could not get a hand in there but it worked.
I tightened it from 3" outside the engine cover about even with the Ski Pole but it worked well.
Thanks

On Intake manifolds and Oil Pans it really saves time and is much lighter than grabbing my Impact gun and air hose. Now I just need to remember to grab it, old habits are hard to break.