Re: 1993 Stratos 274 17ft with Johnson 115
Something doesn’t seem right for sure. I’ve never seen that type of a boat and motor that ran that slow. It’s hard to believe it would require a 15 pitch to perform with that size motor but that’s what the numbers say. Were you able to trim it out to find the best spot to run?
If all of the numbers are accurate and the boat had a normal to light load, it sounds like you need a 15 pitch unless you can find some more HP out of that motor. It might be worth doing a compression check to make sure it’s running strong. Check the throttle to make sure it’s wide open. The timing advance should have been maxed out significantly before the throttle is wide open. I once adjusted the throttle cable so the fast idle was good and to sync up with the gear shift cable and found out the throttle was only about 2/3rds open.
Bottom line is if you can’t find more HP then you’ve got to go with a smaller prop. I hate to mention it but is there a chance the boat is water logged and too heavy? I kind of doubt it but just throwing it out there because I don’t know where it’s been setting over the last few years.
I once had an older 17 foot ranger (not a tri hull) with a Mercury 115 and I ran a fin on the cavitation plate for better hole shot and low to midrange speed. I also ran a Laser II SS prop with exhaust ports that helped with hole shot for skiing and tubing. That boat ran out around 40 mph.
