Re: Repower Mako 17 from 90 HP to 115 HP merc
Originally posted by WillyBWright:<br />23 sounds steep to me. I'd try a 21 first. Your 17 would fit.
I'm with Willy. When spending that kind of cabbage for an outboard your dealer *needs* to make a firm commitment to let you swap props for a few tests till you get the one you need for your use. Don't let them wiggle on this, be firm. That's a lot of money you're laying out, your proper fun is whats paramount.
<br /><br />Now here comes the caution. The "normal" way of propping a boat is to use WOT as the guide. You don't get that luxury because since you're propping down, WOT could be too high to be safe - even for a test. I'd also start with a 21 and watch the tach closely. If it's still pulling past 5200, back off that throttle. Then do your ski testing. What your trying to achieve is having your "ski speed" be between 2200 and 2500.<br /><br />I would also bet that 17 is too low a pitch, with "ski-speed" closer to 3000. That's not bad in and of itself, but at the top end you may be at *great* risk of overrev. <br /><br />Once you settle on the correct prop, you could keep the 17 as a spare if aluminum, or if stainless get $150 for it on Ebay and buy a cheap aluminum spare there - pocketing $100 for your efforts.<br /><br />You're just gonna have to play with it a bit at first to get it set up PROPerly.
<br /> <br />I did something very similar last year when I repowered a 2001 Seaswirl bowrider from a Jonnyrude 115 to a 1987/88 Merc 115. Now in my case, I AM using a 17 pitch SS prop. My ski rpms are about 3000 and my WOT is just short of 6000. I have that luxury because my 115 is the older inline 6 and those will hold together at 6k. Your new inline 4 is known to snap crankshafts at over 5500 as I recall, so you wanna be carefull when you're playing "pick the propeller".<br /><br />Good luck and please let us know what it came out to be!<br /><br />-W
