67 larson 17.5.. outboard swap????

[jesballs57]

hi<br /><br />i have a 1967 larson 17 1/2 feet long, with a same year 80 hp rude(goes 30 mph top speed).id like to swap it for a four stroke. the tag on the boat says it will handle up to a 120 hp.my question is will it handle a 115 four stroke or will the wieght be too much for it?are those old outboards that much lighter than the newer 4 strokes?also how about down sizing?would there be that much proformance loss?... boat is used for fishing in fresh water and in the san francisco bay....any info would help

 

[rickdb1boat]

Re: 67 larson 17.5.. outboard swap????

The NADA guide does not go back that far, but an 1974 85 HP weighs in at 265#. A 120 HP 4 stroke is going to be considerably more. Probably in the neighborhood of 350-400 pounds, depending on brand. Might be a bit much for your hull. You might get away with a 90 HP 4-stroke.<br /><br />For example:<br /><br /> web page<br /><br /> web page 2