buying new outboard, yamaha, 15 or 25hp?

[ron7000]

considering buying a new one this winter.<br />My old evinrude 18 is on it's death bed.<br />I'm not current on outboards, which are the best and which to stay away from.<br /><br />How are the newer yamaha's? Say 2002 and later.<br /><br />Is everything going towards 4-stroke? What the hell's up with the extra weight?<br /><br />If I go the new motor route, I want a 25 vs a 15.<br />Yamaha 2-stroke 15 = 88 lbs<br />Yamaha 2-stroke 25 = 106 lbs<br />Yamaha 4-stroke 15 = 99 lbs<br />Yamaha 4-stroke 25 = 143 lbs<br /><br />I only have yamaha weight #'s handy, but the weights for the merc's were much heavier all around if I remember, and seem to only be 4-stroke now?

 

[yater]

Re: buying new outboard, yamaha, 15 or 25hp?

You should also look into the tohatsus if you're concerned about weight. I have one of their 4strokes and they make a great outboard. ALL of their motors weigh significantly less than the competition and are dead reliable.<br /><br />EDIT: and they're a hell of a lot cheaper than the rest!

 

[Guest]

Re: buying new outboard, yamaha, 15 or 25hp?

Ron:<br /><br />I remember when I first saw the four strokes about 8 years ago. I was blown away by the size. I remember asking if the motor I was looking at was a 25 hp (it was a 9.9 Merc 4 stroke). I wasn't joking, either. <br /><br />I think the've made some progrees since then, though. They're getting lighter and smaller every year. <br /><br />What type of boat do you have? I ask because I had a 15 hp on a 14' boat until a few years ago. There were a lot of times I wished I had a 20 or 25--especially when on larger water. <br /><br />Obvoiusly the weight will be more but if your boat can handle it, you might want to think about that as well.<br /><br />Good luck!

 

[ron7000]

Re: buying new outboard, yamaha, 15 or 25hp?

don't worry, it's gonna be overpowered <br /><br />will have to check out tohatsu...<br /><br />avon RIB 310 Gray, Length: 10'2", Beam: 5'3", Max HP: , Capacity (lb): 1,150, Weight (lb):150<br /><br />has full fiberglass, one-piece bottom and transom

 

[ron7000]

Re: buying new outboard, yamaha, 15 or 25hp?

what i found for specs so far<br />what kills me is merc's 25 is a 3 cylinder, 747cc, and all you get is 25hp? It looks like that it's one model motor from 25 to at least 40hp. Number of and size of cylinders are the same, but weight goes up <br /><br />

     HP    stroke  cyl   borexstroke    cc     weight(lbs)<br />Merc 15       4     2     2.32x2.32    323         111<br />Merc 25efi    4     3     2.56x2.95    747         157<br />Yam  15       2     2     2.20x1.97    246          79<br />Yam  25       2     2     2.64x2.20    395         106<br />toh  15       4     2     2.32x2.36    328         115<br />toh  18       4     2     2.32x2.36    328         115<br />toh  25       4     3     2.32x2.36    492         151<br />toh  30       4     3     2.32x2.36    492         151<br />toh  40       4     3     2.68x2.52    697         210

 

[stan_deezy]

Re: buying new outboard, yamaha, 15 or 25hp?

Very interesting chart because if I'm right, and that doesn't happen very often the Tohatsu 25 and 30 have exactly the same bore and stroke etc <br /><br />Doesn't this suggest that the carb is what is changing the power output or have I missed the obvious (again)

 

[peterc38]

Re: buying new outboard, yamaha, 15 or 25hp?

I have a rope start Honda 20 4 stroke that weighs 108 .lbs. For a small 4 stroke, I think it is one of the best HP to weight ratios. I personally wanted a 4 stroke, but thats why I didn't go with a 25, because there is a big jump in weight.

 

[pwiseman]

Re: buying new outboard, yamaha, 15 or 25hp?

I am told the Merc 25 EFI is a joint project with tohatsu. The current tohatsu 25 will be replaced. If you look at merc the 25, 30, and 40 are all 747 cc. Not a lot of info published, but it sounds like merc block and tohatsu EFI technology combined. compared to other 4 stroke 25s, this is high displacement without excessive weight.<br /><br />I wonder what the heck you are thinking when you say you want a 25 on a 150 lb boat. I think you are very likely to find that the extra weight will cause you many headaches. The bow will want to point to the moon unless you are running hard, and the stern will be sitting too low in the water causing you setup problems. You should be ok if you keep it running over 30 MPH and there are no waves

 

[ivar]

Re: buying new outboard, yamaha, 15 or 25hp?

Isn't the 747cc a Yamaha block? <br /><br />As for the original question, on a 10" RIB , I'd go for a "good 'ol" 25HP 2-stroke, preferably Tohatsu or Yamaha. If you want a 4-stroke I'd check out the Toshiba 18HP as it seems like a pretty good HP/weight ratio.

 

[ron7000]

Re: buying new outboard, yamaha, 15 or 25hp?

Originally posted by Paul Wiseman:<br /> I wonder what the heck you are thinking when you say you want a 25 on a 150 lb boat.

I am thinking speed, duh.<br />potentially I could get a 30 tohatsu on there <br /><br />my current 18hp weighed in at 80lbs and with the raft chambers soft and me at 190lbs standing all the way at the stern with a 50-lb rock resting on top of the motor it still floats fine.<br /><br />The raft is rated for 15hp. So if I buy a merc 15 it is 111 lbs, and I should be a-ok for any motor weighing less than that. A 25 yamaha weighs 106 lbs, has 10 more hp, best go for the buck and best power/weight ratio. Power rating in this case should be irrelevant, if they are at all accurate in the first place.