Re: I need help with my DUO boat and west bend motor
That motor looks to be a Tiger Shark 800, they came out in 1961. Four coils, four plugs, etc, no distributor.
They also made an I/O that used that same motor which laid horizontally in the boat.
Duo boats was at one time part of or started by the owner of Thunderbird, but later, around 1966 or so became part of Starcraft's parent company at the time.
They made a good boat which was sort of an up market model along side of the Starcraft line. The boats were their own designs, not typical sister models as with some brands.
The Duo Rounder model later was replaced with the Gypsy trihull.
The boat looks to be mid to late 60's, in the Starcraft years. I don't think the original Duo company built a trihull.
The two I've owned had a unique sandwiched foam hull, the actual outer hull was made from double layer fiberglass with a thin foam core. There was no other foam in the hull. The lower hull and stringers were open to the bilge and able to better stay dry. They were on the heavy side for boats their side though in my opinion, the Starcraft models were better when it came to overall weight, but the Duo hull was rock solid and rode as good or better than the Starcraft models did. I've owned both and myself preferred the Starcraft trihull over the Duo although the Duo appeared to be a better built boat overall with better materials and better fit and finish. Keep in mind that my comparison is being made after owned both after they were more than 30 years old.