18' Starcraft Offshore Repower

[BMerr509]

Hey guys/gals, i have a thread going in the starcraft rebuild section debuting my 1969 Starcraft offshore tinny. It's 18 ft, weights right at 900#, legally seats 8 and has a weight capacity of 1900#, with a hp rating of 125hp. If you don't know, it has high walls and is incredibly stable in the water. I'm repowering it and that is why i'm here. I'm struggling to decide what to buy. I'm looking for best reliability, efficiency, and it needs to be able to get up on plane. Speed is not a deciding factor for me. it will mostly be used to troll with anyway. Mercs are the cheapest, and it seems like most can agree reliability across all the 4 strokes is comparable. the problem is mercury makes a 60 hp that weighs about 260#, then their next biggest is a 75 that weighs around 360#. Yamaha makes a 70 hp that weighs 260#. Local dealerships support yami/honda/merc. the first question is, will that merc 60 hp make that boat plane?

I know there's a lot of variables here. and i understand i'm underpowering the boat significantly. cost between the 70 yami and 60 merc is within 800$. stepping up to the larger sizes gets pricey quick. what do you all think? I'll be adding a trolling plate to whatever i buy. also, i'll be rebuilding the transom. 2nd question is will the boat be able to support the 360# of the bigger sized 4 strokes? i will not buy an etec so that is out the window. I like the honda's but they are too expensive, and the yami/merc offer what i want at a decent price, but i'm heavily leaning toward merc...

 

[Texasmark]

You are light on your hp aspirations. Do it right and enjoy rather than be kicking yourself for going the cheap route. 100 hp min for that boat. You won't be sorry. How do I know? I had one with a 110 which was ok, but with the family on an outing and trying any kind of water sports, it was barely adequate. Light load and 35 was about it. 35 is ok as far as that goes........a good brisk clip.

 

[BMerr509]

Thanks for the insight Tm- looks like the lighter motors are out of the question for now. I'm looking into the 75-90-115 merc motors, and since they all weigh same, it will come down to the best price between the 90 and 115. Obviously, i would prefer the 115. but the 90 will justify my needs. I do agree that even $800 is worth the extra ponies