Motor Weight Issues

[adidaswolf2]

All:<br /> I have a 1983 Glastron SSV 151 (15.5 ft) and it currently has a 50 hp MERC on her and I want more motor! Right now it runs about 27-28 mph but it is slow to get full speed. Not too good for pulling somone. The boat is rated for 90hp but I wonder about the weight on the transom if I were to find a good 90hp. Any ideas?<br /><br />Or can I just get a better prop and not mess with a good thing? Thanks in advance.

 

[JB]

Re: Motor Weight Issues

50 is not many horses for that boat. My "rule of thumb" says that you need 70% of the rated HP for satisfactory performance.<br /><br />If your transom is sound and the boat is rated for 90hp weight will not be a problem.<br /><br />If you like a bit more maneuverability think about a 70HP.<br /><br />In the meantime, check the Engine FAQ on prop selection. You might be able to improve performance a lot with an ideal prop.

 

[steelespike]

Re: Motor Weight Issues

I believe the rule of thumb is 2/3 of rated horse power minimum for decent performance so you are a little short.<br /> You can put a 90 on with no problem if the boat is sound.<br /> Performance will amaze you.<br /> A prop change depends on your present prop and your present maximum rpm and the max rated rpm.<br /> You can also experiment with motor trim and weight distribution.Trimming in will give a better hole shot but lower top speed.trimming out will give better top end but slower hole shot.Raising the motor vertically can give more speed.If you can raise the motor 1 inch you can gain as much as 3 mph.If there isn't a vertical adjust use 1/4 inch sticks on the top of the transom raise it 1/4 inch at a time until just before ventilation becomes a problem.<br /> Just be sure the mount remains secure on the transom.

 

[Chris1956]

Re: Motor Weight Issues

The weight of some motors went up dramatically since your boat was manufactured. Compare a Merc 150V6 with a 1500 tower of power for example. The good news it that if you stick with a Johnny-rude V4 motor or an inline 3-4, the weight differential shouldn't be too great for your boat.