85hp 1978 johnson and a 1973 larson boat??

[solidwaste75]

I have a 1973 16 foot Larson trihull open bow boat..I bought it about a month ago and it was in ok shape but I decided to fix it up like new again so Ive completely redone the interior and am fairly happy with it..I took it out a week or so ago and it had a 50 hp 1973 evinrude lark on it..The boat ran good through some prety bad waves but was a little slower than id like gps had it top out at about 18mph..The trim tilt went out so I decided to upgrade powerplant..I got a great deal on a 85hp 78 Johnson Javelin,,completely rebuilt by a mech who just loved the engine and it showed..I havent had the chance to get boat out yet Im hopin maybe this weekend..I was just wondering if any one has had any experience with this type of boat and if you think this is too big a motor or just right or to small..Thanks for any input you have...

 

[medic2051]

Re: 85hp 1978 johnson and a 1973 larson boat??

Is there a plate on the hull with a max HP rating? 1973 might be too early for a plate. I have a 15' starcraft 1975. Max HP is around 80.

 

[Pony]

Re: 85hp 1978 johnson and a 1973 larson boat??

I had a 16ft trihull open bow made by duo...It was a 1969 model and it had a plate. Max hp was 85 on it. We ran it with a 60hp 71' Evinrude and we could do 30mph with it. So personally I'd say the 85 seems about right as trihulls are pretty heavy. <br /><br />Good luck