A very simple amp draw question..

[Timm R Oday25]

I'm closing in on finally launching our boat for the summer.
 We've finally acquired the outboard I've longed for.
An electric start 8 horse ,power trim tilt Yamaha four stroke .
I'm seeing a 40 amp draw when I hit the start button .
Does that sound correct ?
I'm also wondering if using a quick disconnect at the motor will induce an even higher current draw.
Part of me wants to leave the motor bolted onto the back of the boat and hard wire it .
The weight of nearly a hundred pounds really kills my willingness to heft up shoulder level to mount it every spring and fall .
I'm also not sure what that much weight on the far back end of the boat will do to my tongue weight .
I'd like to hear your opinions . Thanks

[Charles Brennan]

Timm, Yamaha specifies approximately 120 watts or 10 Amps, for the starter motor on its' 8hp motors.
(A current draw, I am highly skeptical of.)  They further specify starting currents ranging from 10 to 20 Amps during the starting process. 
Timm, being Timm,    you didn't specify whether you have an F8 or a T8, so there can be a lot of play in those numbers.

"I'm seeing a 40 amp draw when I hit the start button .
Does that sound correct?"
A 40 Amp power draw for an 8hp motor sounds a little high at first blush, but there can be a coupla reasons for that.
1) Whatever you're using to read the DC current might have a peak current setting and that would be in the ball park. 
2) The average current draw would have been much less, but unless your meter had some kind of an averaging  setting, you would not see the 10 to 20 Amps figures, cited by Yamaha.
3) An insufficient wire gauge could (temporarily) current-limit the starting current, until the Peukert effect in the battery kicked in and started the motor, albeit with an abnormal current draw reading.

So your cited numbers are a little eye-brow raising, but not necessarily cause for alarm.
We're assuming (since you didn't see fit to tell us!)    that you are using at least #8 AWG wiring and preferably, #6 AWG wiring between the battery and the motor.

"I'm also wondering if using a quick disconnect at the motor will induce an even higher current draw."
Depends on the connector.
A 40 Amp trolling motor connector?    You betcha. 
A 100 Amp Anderson connector?    No Problem.   
https://powerwerx.com/anderson-power-powerpole-sb-connectors?srsltid=AfmBOoq9p1lrfcHZ8c2juoh7ON7cLB-YPkuWZyuCj8i7xlxjiwuUSLdN
You DO know to coat the connectors with silicon dielectric grease, to make a gas-tight connection to avoid corrosion, right?!?

"Part of me wants to leave the motor bolted onto the back of the boat and hard wire it."
Your choice, but I always prefer options, and maximum flexibility generally mitigates against hard-wiring.

"The weight of nearly a hundred pounds really kills my willingness to heft up shoulder level to mount it every spring and fall.
I'm also not sure what that much weight on the far back end of the boat will do to my tongue weight."
Preaching to the Choir, Brother.
I have had a 115 pound 15hp Johnson hanging off the back of Urchin, for the past 30 years.
You cannot view this attachment.

While trailering, it has a safety cable to keep it from ending up going through somebody's windshield and it also has a ratchet strap, to keep from rattling on the bracket and ovaling out the bracket pivots.
It's been on or off the transom mounting bracket probably less than a dozen times.
(And my back remembers EVERY. Single. One. of those times!) 
You cannot view this attachment.
Small black line towards top of transom is the safety cable.
Black nylon strap around motor, prevents road travel movement.

Reinforced the transom area internally, with ⅛-inch aluminum plate, against a ½-inch marine plywood backer board and then glassed in place.
1) Measured my tongue weight,
2) Installed the motor on the transom.
3) Measured tongue weight again.
4) Moved the trailer spring side hangers back, until I regained my previous tongue weight.
Only required a few inches, IIRC, about 3 iterations, before I was happy.

Hope this helps,
Charles Brennan

[Timm R Oday25]

Charles ,somehow I knew you would respond .
As far as I could find out both versions of the motor use the same powerhead .
As you can only start the motor in neutral ,the amp draw would be the same .As I understand it the outdrive and the prop are the only difference .
The wiring is factory 6 gauge Yamaha maybe 8'.
I really am reluctant to cut it in half and add quick disconnects . My thinking is that this is just another place for corrosion and increased amp draw .
I had thought I would use the factory harness and route the wires under the cockpit . The thought of another 100 pounds bouncing off the very far end of the boat had me concerned . Thanks for taking the time to answer sir