what are some simple ways to increase power?

imshirazy · Outlaw Joined: 01 Jul 2008 Posts: 117

Hey guys...I live with my parents and therefore cannot buy my own boat for wakeboarding. I use a 115 HP outboard 17 foot boat. Needless to say it's weak, it gets the job done but not if i have more than 4 people (lol). What are some simple ways to increase power?
I figured:

* higher end spark plugs
* higher pitch propeller?
* better battery?

I do a lot of car work, but things like intakes and exhausts don't seem to be applicable to an outboard engine. What else can I do? since it's my father's boat, he doesnt want me doing anything crazy like high compression pistons lol

882001 · Posted: Feb 21, 2010 11:10 am Post subject:

drop pitch of prop

beretta5spd · Posted: Feb 21, 2010 12:33 pm Post subject:

I own a 16 ft boat with a 115 on it. Not sure what pitch I have but it's enough to pull 5 boarders at once and still hit 40 mph.

Northeast · Criminal Joined: 22 Dec 2005 Posts: 78

115 hp should work fine on that boat for boarding. Not with 2,000# of ballast or anything but basic wakeboarding with 4 in the boat should be no problem. I used to go behind a boat with a 70hp. Like others said buy a new prop with lower pitch.

Northeast · Criminal Joined: 22 Dec 2005 Posts: 78

BTW: do NOT try to modify that engine to get more power out of it. Any gains you might get out of it (unlikely) will be offset by likely problems you will run into plus the "story" you will add to the engine/boat combination when it is time to sell it. It is also tough to achieve noticeable power gains in marine applications as compared to automotive ones.

JUST-IN-TIME · Posted: Feb 21, 2010 4:23 pm Post subject:

4 blade prop
clean carbs
clean fuel
good 2 stroke oil
clean spark plugs

imshirazy · Outlaw Joined: 01 Jul 2008 Posts: 117

Thanks for the suggestions so far, I guess I can't do much about the engine except spark plugs, clean the carb, and good fuel.

Second question then...I can only imagine that a different propeller will do a huge difference, considering pitch/surface area/weight etc can be a factor.
I have absolutely no idea about props...I understand there's a few diff types, I currently have a 3 blade aluminum (with slight damages like nicks). What should I look for? The bronze/nibrals seem nice but also looks as though they are only meant for inboards (i have outboard). Should I be aiming for stainless or composite over aluminum? What pitch should I look for etc? I did some research but it's all very vague

JUST-IN-TIME · Posted: Feb 21, 2010 6:47 pm Post subject:

Stainless will reduce top speed but give better hole shot

we need to find out what wot rpm are first

imshirazy · Outlaw Joined: 01 Jul 2008 Posts: 117

this engine
http://www.outboardmotor.net/motors/184.html

I'm assuming the WOT rpm is the 4500-5500
which seems about right when I floor it, at least what i remember from when the tach used to work lol

also isn't stainless the heaviest prop type? And what do you mean by hole shot? turning?

JUST-IN-TIME · Posted: Feb 21, 2010 7:12 pm Post subject:

yes 5500 is good

5300 is ideal with a 80% loaded boat

get a good tach!!

imshirazy · Outlaw Joined: 01 Jul 2008 Posts: 117

Tach is already on the list anyway.
But still, what about the prop and what's a hole shot?

STANG KILLA SS · Posted: Feb 21, 2010 7:46 pm Post subject:

less prop pitch.

remove some weight.

JUST-IN-TIME · Posted: Feb 21, 2010 7:54 pm Post subject:

hole shot

that is like reaction time when drag racing

beretta5spd · Posted: Feb 21, 2010 9:24 pm Post subject:

Hole shot is your acceleration fromm a dead stop.

homelandairtap · Criminal Joined: 09 Jan 2010 Posts: 53

the only thing about getting a SS prop is if u ever hit anything it might do alot more damage appossed to a aluminum prop.

pet575 · Posted: Feb 23, 2010 7:58 am Post subject:

Hollywood · Posted: Feb 23, 2010 8:21 am Post subject:

For your Father's sake, please do not touch the engine.

JUST-IN-TIME · Posted: Feb 23, 2010 10:53 am Post subject:

pet575

i have seen gearcases ripped off from stainless props

but i could not tell if a AL prop would have helped

STANG KILLA SS · Posted: Feb 23, 2010 11:49 am Post subject:

imshirazy · Outlaw Joined: 01 Jul 2008 Posts: 117

Ok so 4 blade makes sense with a lower pitch
doesnt make sense to me how that helps with pull though...I thought lowering pitch increases resistance, and i KNOW increased prop weight will increase resistance