Another question about a bigger motor

[jsfinn]

A while ago, I asked about the biggest safest motor I could put on my 12 foot semi-v aluminum starcraft boat. It doesn't have a plate with the manufactures ratings because it's too old for that, and if it did, the previous owner removed it. I didn't get the exact answer I was looking for (nobody told me NOT to put 15 HP on it - and nobody said to go ahead and do it) and am still unsure but from the USCG information, I think 15 HP is what they rate my boat for.<br /><br />My question is - Is 15 HP too much? Also, I can get a good deal on an 18 HP motor which is such a small difference from 15 HP is it really going to matter?<br /><br />I don't want to do anything unsafe - but I want the biggest motor I can get without danger.<br /><br />Just an FYI - I currently have a 5 HP on it and it won't plane the boat with me and my too-much-gear. I think a 10 would if it was just me in it - with a 2nd person, I think I'd be back down under the water.<br /><br />Thanks!

 

[LubeDude]

Re: Another question about a bigger motor

I personally see no reason you cant run the 15 or the 18! You and your gear should be enough weight to settle down the boat. After all you do not have to run WOT all the time! Use your head and wear your life jacket! Maybe look dumb, Maybe, Save your life, Yes! I always wear my life vest in my Bass boat anytime the motor is running!<br /><br />LubeDude

 

[cobra 3.0]

Re: Another question about a bigger motor

Go with the 15 instead of the 18. The 15 weighs the same as the 9.9.(the 15 only revs higher) and my guess is that your boat is rated for a 9.9. Most 12 ft aluminums are. Here is the new 12 ft Starcraft It is rated for 10 hp. <br /><br /> http://www.starcraftmarine.com/showroom/specs.php?boat=SeaLite+12&img=sealite12 <br /><br />The 18 will likely be too heavy for your boat. The 15 is a far smoother engine at idle and trolling speed too.<br /><br />I had an 18 Merc and now have a 15 Evinrude on a 14 ft. aluminum. The 15 goes almost as fast and is much more pleasant to use(quieter and less shake at idle).

 

[jsfinn]

Re: Another question about a bigger motor

Thanks LubeDude. That's kind of what I was thinking too - WOT only on a calm day between the bends - but I guess I won't really know how it handles until I try it... I wish there was some sort of service that would let you rent motors to see how they work on your boat.

 

[cobra 3.0]

Re: Another question about a bigger motor

...I still say the 18 is too much weight.

 

[Solittle]

Re: Another question about a bigger motor

I have a 12'er just like yours and run a 1975 OMC 9.9 on it. Gets the wife & I up on a plane just fine - - and it is a long shaft (a no no to some but works for me).

 

[Solittle]

Re: Another question about a bigger motor

I have a 12'er just like yours and run a 1975 OMC 9.9 on it. Gets the wife & I up on a plane just fine - - and it is a long shaft (a no no to some but works for me).

 

[jsfinn]

Re: Another question about a bigger motor

Cobra, Thanks. I didn't think about the weight and idle of the 18HP. For the 3 extra horses, It's probably not worth the added weight.<br /><br />I saw the new Starcrafts are rated for 10 HP. Mine is a 1963. I guess the hull is stronger and maybe wider - not really sure.<br /><br />I've thought hard about just getting the 10 HP (better safe than sorry), but I really think that I'll always wish I had a 15 if I went with a 10.<br /><br />Unless anyone seriously thinks that this is a mistake, I'm going with a 15.<br /><br />(I hope I'm not making a bigger deal of of this that I really should - 5HP is really a big deal on a boat this small..)

 

[cobra 3.0]

Re: Another question about a bigger motor

I think the 15 hp. is one sweet motor! The extra 5 hp is nice to have and gives it the extra umph that makes you go WOW! I had a 7.5 hp Merc that was pretty good and could get my boat on plane with two people, but was a "slouch" with three. The 9.9 had a little more guts, but the 15 really kicks! I think its the best little engine bar none...

 

[cjones4@hvc.rr.com]

Re: Another question about a bigger motor

I have a Starcraft brochure from 1967 that shows the following 12' aluminum boats and their specs:<br /><br />12' Super Star - center length = 12'1",gunwale lenth = 12'8", beam = 57",bow depth = 24", transom width = 50", capacity H.P. = 15<br /><br />12' Sea Scamp - center length = 12' ,gunwale lenth = 12'6", beam = 52",bow depth = 22", transom width = 45", capacity H.P. = 10<br /><br /> I know this is not the exact same year but maybe using these dimensions you can determine the correct capacity H.P. for the boat you own.

 

[Hooty]

Re: Another question about a bigger motor

Put tha 15 on it, invest $35 and install a TinyTach so you can get it proped right, raise the engine up on the transom until it cavitates when turning then drop it down 1/4" and you'll be fixed. I'd do the setup with only you and your gear in the boat. That way with two people, it won't be all lugged down.<br /><br />c/6<br />Hooty TinyTach

 

[jsfinn]

Re: Another question about a bigger motor

Excellent. Thanks guys - I'm feeling a lot better about this now that I did before.<br /><br />Any other comments?