Hi guys,<br />I have a 2000 "Mercury Mouse" boat.It has a 15HP<br />2 stroke.My problem is that the the motor will only reach 4800 Rpm WOT using a 9" pitch prop.If I use a 7P it will turn 5200 RPM.This brings it within spec,(5000-6000) BUT I lose top speed by about 4MPH.<br />There are several other boats like mine on the lake and they are all much faster and sound it to!(By the sound they are turning about 6000 Rpm)<br />I have a Tac on mine.<br />Is there a adjustment for max RPM? <br />I have checked my plugs and made sure that the carb butter fly opens all the way.<br />Any idea's?<br />Thanks.<br />Rafi
Generally you will loose top end when going to a lower pitch prop. The RPM's are not adjustable per-say. They are determined by the load being propelled, prop configuration and motor setup. To try and get more revs out of the existing prop you could try raising the motor higher on the transom. Less motor in the water = less drag and higher RPM. At some point the prop will ventilate though so there is a limit on how high you can go. Also be careful not to restrict the water intake. Where is the anti-ventilation plate relative to the bottom of the boat ? What trim angle are you running at ?