How do I test Yamaha 115's battery isolator?

I have a 115 V4 Yamaha 2 stroke outboard (pre-1992 model).
It has sat for 3 years and after connecting a new battery, I hear
clicking instead of the starter attempting to kick over. I've traced
power to the Hitachi 12V A104-127 battery isolator mounted on
the motor. However, power is not passing thru this isolator.
It is the isolator that 'clicks' and vibrates a little as I attempt
to start the motor. My question is, how do I test the isolator?
Also, can I bypass the isolator and directly connect the starter
to power and ground to confirm the starter is still good or might
this damage the starter?
I'm a backyard chevy muscle car mechanic. Not an outboard mechanic.
Could use any direction/suggestions anyone might have.
Thanks!

[boats.net]

That motor didn't have a factory installed isolator and not sure how they have it wired up but I wouldn't think an isolator would be in the starting circuit.

Mistaken Identity of Isolator?

First of all, thanks for taking the time to respond and share!

I most likely, then have mis-identified the suspect part.
The Yamaha Outboard's tag shows it to be a Model# is 115ETLH with a 6E5 and L indicator under the model# tag. I'm not positive of the year because
it came on a 1980 Ranger that I purchased in May of 1992. The motor was
not the original for the boat.
The part that I have traced the 'clicking' to is mounted on the passenger side of the bow-facing part of the motor. It is a square-looking apparatus approximately 2"x2" in size. It is surrounded by a black rubber, removable boot whose purpose appears to not only to be to insulate the item but has slots cut out on each side for mounting it to the motor. There are two large posts w/nuts on opposite diagnal corners and two smaller screws on the other two opposite corners. One of the larger screws had a large Red positive wire nutted down to it. The black 'negative' wire paired with it went to the starter. The opposite large post/nut had a shorter (but same gauge) wire leading from it
to the other (I believe 'Positive') side of the starter.
When I placed a meter on the feed positive and negative starter posts I showed voltage. When I switched the positive meter needle to touch the shorter wire to the starter, I got nothing. Even after turning the key to start the motor.
In addition to the two large posts to which the larger wires attach, there is also a smaller black ground wire and a light brown wire of similar gauge size that appears to be routed to the second position down from the top of the fuse box located on the opposite side of the motor. These two wires (both the black and brown are soddered to the part in question with an in-line coupling in use to extend the brown wire to the fuse box.

The back-side of the part is round and labeled Hitachi 12V A104-127.

Based upon the above, I'm hoping you can identify what it is as I believe it to be why the motor won't even begin to kick the starter over. (THIS IS A GUESS!).

When I searched the intranet for the Hitachi item numbers, it led me to believe it was some sort of Battery Isolator. Hence the identity issue!

Thanks for any assistance you can provide me.

~ern