Tweaking my Force 9.9

Can anyone tell me exactly what the best way to get a few more hp out of my 94' Force 9.9 would be? I'm considering trying out a 15 horse carb but is there more to it than that? I noticed that according to Mercury's spec sheet, the main difference between the 9.9 and the 15 is the max PPM and the 9.9 has a 7.4 kw rating while the 15 has an 11.2 one. Is there a rev limiting system that I can disable? Should I have any other questions? Any help would be heeded and appreciated. Thanks,<br /><br />Rich Pierro<br />rich@pianorebuilder.com

Re: Tweaking my Force 9.9

Hi<br />There is no rev limiter on the motor.<br />I have never tried it. If the port timing is the same it should work. You may have to do some minor engenring but not bad.<br />...have fun...corm

Re: Tweaking my Force 9.9

Hi, Rich. About 90% of the time when guys seek a little more power from a small outboard there is twice as much opportunity at half the cost available in tuning the boat... and leaving the engine alone.<br /><br />Is your bottom slick and clean? Worth half you engine's hp alone.<br /><br />Is your depth on the prop optimum?<br /><br />Is your tilt optimum? <br /><br />How much excess, and unneeded weight is aboard?<br /><br />Where is the center of gravity? <br /><br />Do you have the right prop?<br /><br />Is it in perfect condition?<br /><br />Six more horsepower cannot overcome the wrong answers to the above.<br /><br />It is true that enough horsepower can make a barn door fly, but a LOT less money can make a kite fly.<br /><br />Red sky at night. . .<br />JB

Re: Tweaking my Force 9.9

The boat is a 14' Lowe aluminum fishing boat. It's 67" wide and it's a semi-v. It's about 1 year old and doesn't get left in the water, it's perfectly clean. I've tried 3 props and the one I have now gets the most power and speed. I've tried to adjust the prop height and angle, but I don't have much flex there. the angle adjustments are to extreme, and I can't really move the motor up on the transom. The prop is brand new and I don't carry unneeded gear while fishing. The boat planes off with one person but not really with 2. If it's me and my wife it almost planes and we get about 13 to 14 mph. If I'm with any of my friends (much larger and heavier than my wife) it doesn't break 10 mph and it slugs along plowing through the water. I think with a few more hp I might get over the top and on plane. Does anyone think I'm nuts?

Re: Tweaking my Force 9.9

No, Rich. You're not nuts.<br /><br />Sounds like there is little room for improvement in your boat. A shorter prop might get you on plane, but without a tachometer you just have to guess whether the engine is getting to its best operating range.<br /><br />As I recall my own 14 semi-Vee from years ago, I think It was rated for 20 HP and I ran an OMC 18 on it. It planed easily with 2 big guys and a boy in it. When I took it to those "10 or less" lakes I used an OMC 5.5 and it wouldn't plane with just me in it. Does that sound like your boat?<br /><br />I think you need a bigger engine. I don't think hopping up the 9.9 will get you noticably closer to what you want unless you are trying to cheat on the "under 10" waters.<br /><br />Red sky at night. . .<br />JB

Re: Tweaking my Force 9.9

My dad's 14' has a 9.9 force which is the same motor and it planes with 3 adults in it. It is more a flat bottomed than a vee and that probably makes the difference. <br /><br />Have you considered trying a Doel Fin. It should help you plane easier. If you can get on plane, your RPMS will come up and you will go faster. Also, look at weight distribution. Move momma to the front..