21' Starcraft Holiday with 90hp Yamaha - Underpowered?

bchaney

Petty Officer 1st Class
Joined
Jul 3, 2018
Messages
246
Hey guys, came across an old 72 Starcraft Holiday with an 08 Yamaha 90hp 4-stroke. It's a nice motor but is it too small for this boat? According to the specs on iboats and nada the boat weighs 1400-1500lbs empty so probably 2500-3000lb when fully loaded with people, gear, fuel, etc. Max HP on the plate is 170hp but that's probably crank rated HP due to the age of the boat. I've read on these forums that most people recommend staying at 75% rated HP or above, but this setup is lower than that. Seller says the boat tops out at 35-40mph which sounds like plenty to me if it's realistic. Boat would mostly be used for cruising around, some tubing and fishing. Any thoughts? Thanks.
 

mr 88

Commander
Joined
Nov 3, 2010
Messages
2,219
Don't think they made a 170 hp outboard in 72,unless you ran twins to hit that number. Could also be rating for a I/O. Have a 18' StarCraft pretty much stripped out for a waterfowl platform and have a Merc Tower from the 70's on it crank rated at 90 hp. I have no problem getting her up on a plane and running 35mph with 5 adults and a ton of hunting equipment on it. 17" SS prop on it. Best thing to do is take her for a test ride, but I would go along with what the seller says and the engine being a 4 stroke and much newer should give you plenty of low end grunt to meet all your needs !
 

Watermann

Starmada Splash of the Year 2014
Joined
Jan 12, 2013
Messages
13,822
I think a newer 90 HP on a 21' Holiday would a bare minimum with a 150 being optimal. I can see 35 mph lightly loaded with the 90.
 

BWR1953

Admiral
Joined
Jan 23, 2009
Messages
6,280
Yeah, I'm thinking that it needs another 90 sitting right next to the first one! :D :lol:
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,957
I'm thinking a lot of what you "need" is going to depend on how you plan on using this boat. It shouldn't have any trouble pulling the grand kids around on a tube. When it get to more than that, it's going to depend on how much more you are thinking.
 
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