How big of a motor?

[jsfinn]

Hello,<br /><br />I have an old 1960something v-hull 12 foot Starcraft aluminum boat. It currently has a 5 HP Gamefisher on it that just isn't big enough to get the boat on plane (or anywhere fast) so I want to upgrade to a bigger, better motor.<br /><br />The boat doesn't have a plate with it's max HP rating, and from reading the forums, it looks like most people put a 9.9/10 HP on their 12 footers. If I put 15 HP on it, will it be dangerous? Also, it seems like a lot of the 10+ HP motors have electric starters on them. Does that mean that they also charge the battery or is that just a feature of bigger motors?<br /><br />Thanks!<br /><br />Josh

 

[DJ]

Re: How big of a motor?

Josh,<br /><br />I doubt your boat is rated for much more than 10. A 9.9 will probably plane it.<br /><br />iboats has some nice 9.9's on sale now for $999.00.<br /><br />Small engines that have electric starters do not always have electrical charging capability. In the case of John/Rudes, there weere two seperate kits, one for starting and one for charging. They could be used alone or in any combination.

 

[jsfinn]

Re: How big of a motor?

Thanks for the info. I think I am going to go with a 9.9, but still curious if a 15 would be dangerous? What are the hazzards? Does the boat become unstable? If it's not dangerous, what are the gains? Will I get a lot more speed or just a couple of MPH?<br /><br />I don't want to make the boat unsafe, but I certainly want to get the most out of the boat that I can.<br /><br />Thanks!

 

[kenneths]

Re: How big of a motor?

I've got a 12ft starcraft deep-V that's rated for 15hp, but I've got a 54' 10hp Jonny on it......Plate is right on the face of the transom... <br />It "could" be dangerous with only you in the back and operate in a careless manner, but any boat will be that way-common sense here....

 

[streadway]

Re: How big of a motor?

i had a 12 ft v-bottom with a 15 evin on it,it was a heavier grade boat. it did just fine.it would depend on the weight of your boat.my new 9.9 merc elec. charges the batt.

 

[jsfinn]

Re: How big of a motor?

Carp King,<br /><br />Why did you put on a smaller motor? Do you notice a big difference? What happend to the 15 evin?<br /><br />I don't know the weight of the boat, but it's an old one, and seems sturdy to me.<br /><br />Thanks

 

[Solittle]

Re: How big of a motor?

Josh - You should be quite happy with the 9.9. I run a 1975 9.9 on 13' skiff & performance is quite satisfactory. The 9.9 is actually a 15 in sheeps clothing. The 9.9 rating came about, I understand, because many states did not require that a boat with a motor of less than 10 hp be registered. There are minor differences between the motors.

 

[sloopy]

Re: How big of a motor?

I have a 12 foot aluminum gamefisher from sears. The plates says that the maximum horsepower allowed on the boat is 15. I use a five horse power Briggs and stratton with Davis Dual fins and at full throttle it goes 19-20 with one person on board. If I load it up (3 people and lots of crap) it will go thirteen.

 

[OBJ]

Re: How big of a motor?

Hey Sloopy...you draggin yer toes agin ta' measure speed??

 

[streadway]

Re: How big of a motor?

jsfinn i sold that boat and went to a john boat for river fishing.i wanted a new motor since i retired last year and did not want to work on old motors.and i got the 9.9 merc.at a great price.i fish out of a 12' alumacraft light weight boat.with me 210# two batteries and all my gear.the boat runs at around 20 mph and handles very well.with my wife up front around 15 mph.

 

[sloopy]

Re: How big of a motor?

No I was using a Garmin Etrex GPS, I had a full tempo three gallon tank with me with two oars on each side, and a boathook in the bow. Max speed out of 3 runs was 19.5 20.4 20.3. I did the test on a calm day over 1 mile. (three miles total)

 

[jsfinn]

Re: How big of a motor?

Thanks for the info everyone. Anyone else have any comments?

 

[crazy charlie]

Re: How big of a motor?

Dont be concerned with getting a 9.9 or a 15hp Most are exactly the same motors,some just rev higher and some have different carbs. But they are the same motors.I dont think you would even notice much of a difference between the two unless you have the motor full throttle.Charlie

 

[flydangler]

Re: How big of a motor?

Way back on November 28th Sloopy said "I use a five horse power Briggs and stratton with Davis Dual fins and at full throttle it goes 19-20 with one person on board".<br /><br />Okay, I've searched all over the place and the only place I've found any mention of "Davis Dual fins" is on this forum, in this thread. What the heck are they?