whats a good 25hp?

[ber1023]

I need a 25hp for a "winrace" www.winrace.no/index_eng.php, something that is light (around 112lbs) and that can be modified a lot. I have a merc 25 but with its nickasil walls and no head its a pain because i cant raise compression. What do you think about selva or tohatsu 25hps?

thanks

[ZUL8TR]

25 hp

The Merc 25ss (1973 -1980) is about 25 hp and about 65 lbs but raising compression is not easy like your Merc 25.

Not familiar with the Winrace but how about 30 hp and get a Yamato Y80? Compression is easily to raise by milling the head. Pipes can be added. They weigh about 85 lbs and are bullit proof.

[B Walker]

I am not familiar with winrace either but if you have to use those V-Hulls in the pictures I am certain a 4 stroke will outperform an equvalent hp 2 stroke on that type of hull. Especially on the European style narrow river courses.

The US does not have much experience with modifying small 4 stroke outboards. Almost all small outboard racing in the US is still 2 strokes.

Brad Walker

[johnsonm50]

I am not familiar with winrace either but if you have to use those V-Hulls in the pictures I am certain a 4 stroke will outperform an equvalent hp 2 stroke on that type of hull. Especially on the European style narrow river courses.

The US does not have much experience with modifying small 4 stroke outboards. Almost all small outboard racing in the US is still 2 strokes.

Brad Walker

Thats probably true of the 4 strokes, usually yielding a much wider power band. Weight could be an issue with them.

[ber1023]

yah i think 4 strokes weight to much and i prefer 2 stroke as i know how to work on them.

[hyrobuzzie]

hey there mate in australia we mosty run with the 25hp tohatsu run a b cast block with c electiric is the best formula , advance the time to 27deg, u need to run a 4 thou piston clearance in your bore to help stop it niping up and the end of the str8 remove the carb restirctor , there are so tach pick up and rev limits under the fly wheel that u will need to remove and you will have a nice quick race motor ,