Prop choice ????

Hi gentelmen,

I've got a Merc 200 1998 with a 17 inch prop 15 pitch,she runs at 5800 72 kph but I would like to bring the rpm down to have a good plain speed.

Its fitted to a aqausport 222.What prop can you recomend I do not want to kill my engine or damage it with high rpm's.

Any idea's ???

Re: Prop choice ????

5800 is right on the perfect RPM for that motor.. no reason to change, keep it under 6K and you will not have any damage to the engine from RPMs.

Re: Prop choice ????

At the risk of being nit picky there are apparently 7 distinct 200s 3 different rpm ratings
2 different gear ratios at least in my source.Optimax,off shore,off shore efi,efi,merc 200.
A marine motor works very hard like its allways going uphill.If you prop to force a lower rpm its like making it go up that hill in overdrive.It will struggle more on hole shot and work harder with a load not to mention the constant struggle just to push the boat uphill so to speak.
The motor needs to rev freely within its rpm range.

Re: Prop choice ????

Thanks Gentelmen,

The Merc 200 off shore serries(two stroke) is a fantastic engine,on the take off she launches out of the water like a bat out of hell.In the Caribean water is genaraly flat and fantastic and just to cruzaroun on 3000-3500 rmp is good but would have liked to add a little more speed to that rpm or the same speed with lower rpm.

Thanks for the responce.

Re: Prop choice ????

you need to find out the factory recommended RPM range for your motor, over propping can lug your motor and damage it, I suspect the prop you have is just right, most 2 stroke outboards love the 5800 WOT RPM range. what you are trying to do is NOT the way to go. you HAVE TO prop for WOT RPMs, not mid range. If your factory recommended range is in the low 5Ks, then you may could go up 2 pitches, but you will burn about the same gas as before and lose some hole shot. trying to get higher speed at a certain RPM is wrong thinking, if you want to go faster press the throttle forward...I mean there is nothing special about 3000-3500 RPMs, you are not going to increase the life of your motor by running at lower RPMs.

Re: Prop choice ????

Thank you very much for the advice.