Repowering with heavier outboard motor

[eagle787]

Hi, My son & I are planing on repowering a 1986 or 1987
Blue Fin S170 17' Aluminum Boat it's rated for 90 HP Max. Original motor Force 85 @ 250 LBS
WE want to repower with a
4-Stroke Yamaha F90 @ 350 LBS
Also adding a kicker/emergency motor Honda BF15 @110 LBS. If my math is right, that's an extra 210 pounds more than. Our question is
Will that be too much added weight?
We can't put BOAT in water and add 220 lbs to stern to kinda test it, because we're replacing the rotting transom & redoing the decking.
I'll try to add photos
Thanks for reading appreciate any replies

 

[GA_Boater]

Deduct the weight of the CMC TnT unit, 45 pounds. Your down, or up, to 165 pounds. Are you replacing the flotation foam? If so, that's less weight in the boat.

Without the setback of the CMC the 165 pounds will have less of an effect.

 

[eagle787]

Deduct the weight of the CMC TnT unit, 45 pounds. Your down, or up, to 165 pounds. Are you replacing the flotation foam? If so, that's less weight in the boat.

Without the setback of the CMC the 165 pounds will have less of an effect.

Oh ya that's right I didn't even think about that. yes the flotation foam will be replaced, and the CMC bracket won't be needed..Shedding weight already, thank you

 

[Chris1956]

If you can put the old motor back on the transom and launch the boat. Now walk to the transom (you are 250# right), or get your son to add his weight and see how much she lowers in the water.

 

[eagle787]

remounting old motor is an option , don't even need to hook up just clamp it launch it while my son holds a rope and pulls it over to the dock. thanks