Modifying an outboard motor for more power!

[keep_itsimple]

I want to get see if there is a cheap option rather than changing my outboard to a bigger one, to get more power. At the end of the day its just a motor, is there cheap mods you can do? Ive got a bf90 honda 4 stroke with carbs

[keep_itsimple]

I have also a 15 yamaha 2 stroke that i want to tinker with

[Normoh]

You can bore them out, but I wouldn't really call it a cheap option

[MattyA]

Supercharge that mo fo

[bender]

cheapest option -

1 - get the prop tuned
2 - use quality fuel
3 - use the best plugs
4 - carry less gear
5 - go on a diet
6 - only take your smallest mates
7 - never drive into the wind


OR BUY A MERCURY ....

[tweedz]

Unfortunately, once you start playing around with anything mechanical its never cheap.
You know the old saying....If its got wheels or boobs it'll cost you money.
If it floats....double it!

[keep_itsimple]

So you can't change the jets in the carb or change some intake parts or anything?

[Bream Ville]

Have u looked into a 4 blade solas prop

[Normoh]

You can change jets, but power gain is negligible. That's mostly done too help motors run smoother at different altitudes. Not sure if the intakes are restricted or not

[keep_itsimple]

I rang solas and they told me to start off on a 13.25x17. I'm getting that shortly but I thought there would be something I could do to perk it up

[scottyfish]

With the 2 stroke you could see if Boysen do power reeds for your model. I hear they make a bit of an improvement.

As for the 4 stoke..normal stuff...more air +more fuel = more power...so anything you can do to assist in those will help..a good tune, clean carbys and decent plugs. when it comes to cracking the motor open..as said before, bigger pistons,cam change tune etc...but yeah it gets expensive. might be better to repower.

[thecheif]

hey champ ill give it to you straight ive got two boats and my primary focus has been top end which in turn you sacrifice hole shot so you need to decide what you want to acheive i have a 445 hornet trophy with a 60 hp honda 4 stroke i get 30 knots loaded with a 13 pitch prop not much hole shot but gain is top end same as the other 5.8 mtr genesis craft twin 90hp 4 stroke suzis hole shot not great but top end 40 knots 22 pitch cupped props dont worry about mechanical engine mods not worth the outcome rather tune your props to your running eviroment will give you the best result dont forget trimming your boat out properly will give you the greatest gains pm me if you want more detail the guy at soalas her in perth are great props are good to

regards thecheif

[keep_itsimple]

Thanks for all the advice, I will be getting the new prop in the coming weeks and hopefully will make a big improvement. Does a hydrofoil make much difference on bigger motors?

[MattyA]

Originally Posted by keep_itsimple

Thanks for all the advice, I will be getting the new prop in the coming weeks and hopefully will make a big improvement. Does a hydrofoil make much difference on bigger motors?

They make you plane easier at lower speeds, we found they dropped top speed by 3-4km/h. If youre looking for WOT performance then stay away from them. Just my experience with em.

[Piranha]

Originally Posted by bender

OR BUY A MERCURY ....

He want's to go faster and you recommend a brand of anchor?