200HP won't start

I have an '02, 200HP 2cycle Yamaha that I bought last year on a Skeeter SL190. Normally, it runs like a scalded dog. Idles smooth, easy, quick starting.
But...
once in a while, it just won't start. Sometimes it's cold, sometimes after it's been run, hot weather, cold weather, makes no difference.
I turn the key and all I hear is a clicking noise from the motor.
Guessing a starter solenoid?
I've run whole weekends with nary a problem. Next time out, it won't start to get it off the trailer. No rhyme, no reason. Nothing consistent.

Anybody else out there ever have this problem?
I REALLY need to get this fixed, because the Wife refuses to go out with me until I get it fixed....hey....wait a minute...would that necessarily be a bad thing?...JUST KIDDING !!!
Any help/suggestions would be appreciated.
David

[boats.net]

If it's clicking when key is in start position then thats the starter solenoid clicking. That could be a bad solenoid, bad starter or wiring problem on one of the two.

...when I stated that all I hear is a clicking noise, I mean that it clicks one time with each turn of the key.
Thanks for the suggestions...they both sound expensive .
David

[jb123]

Ensure you have 12v + at relay and also starter as you may have a voltage drop somewhere.

use a jumper cable from a known hot batt, connect to the starter lead, see if it turns strong everytime to try to isolate your prob.