More hp from Mercury 90hp 4-stroke

[saittam]

I have a Mercury 90hp 4-stroke engine from 2000.<br /><br />1.) Is it possible to tune the engine to be able to receive more horse power?<br /><br />2.) What kind of prop is recommended to achieve the greatest top speed?<br /><br />/Mattias

 

[steelespike]

Re: More hp from Mercury 90hp 4-stroke

Cant tell you about tuning.<br />As far as the prop goes well need to know<br /> the prop you have now and your present rpm<br /> and the max reccomended rpm.<br /> Wouldnt hurt to know what type and weight boat.

 

[saittam]

Re: More hp from Mercury 90hp 4-stroke

The Engine is mounted on a boat called Silver Hawk.<br />Length: 5.2m<br />Weight: 550kg (boat 380kg + engine 170kg)<br />Prop: www.propulse.se<br />Prop diameter: 13”<br />Prop pitch: 16”-20” (adjustable)<br />Max rpm: 6000rpm<br />Rpm with today’s prop: 5800rpm

 

[Spidybot]

Re: More hp from Mercury 90hp 4-stroke

Hejsan Matthias,<br /><br />Your setup is pretty close to perfect, based on the figures.<br /><br />More speed would be possible by tweaking the setup (x-dimension), trim and the pitch. You will have to decide wether you want max top end or max hole shot.<br /><br />Your prop is good, handy regarding the adjustable pitch but not a hi-performance design. If you spend the SEK's you could get a prop with better bow lift and get a few more knots on the top.<br /><br />Your boat/motor theoretically runs 51-57 mph at 5800 rpm with a 21 or 23 pitch (depending on your hull design). About the same top speed with a 20 pitch at 6000, but better hole shot.

 

[saittam]

Re: More hp from Mercury 90hp 4-stroke

What hi-performance prop whould fit this engine?

 

[Spidybot]

Re: More hp from Mercury 90hp 4-stroke

Hi perf props comes in more types. Apart from the extreme types, used for pure racing, a performance prop for your motor could be Quicksilvers own SS range, Precision Propellsers's 'Turbo' or maybe one of those on the link, bottom of this page. Make sure you specify your motor right as not all Merc's fit the same props.<br /><br />Remember that 'moms' and customs will be added if you purchase outside the EU.