Force Prop help

[Bonstrosity]

I have a 1986 bayliner capri 16 foot with a force 85 motor and ended up with a michigan wheel vortex 13.25x17 prop which works great when there is nothing on the boat. When I'm out with other people or out fishing w/ my equipment I can not seem to make it up to full WOT rpms. I can only make it to about 4800 when I should be able to get up to 5500. Would I be able to buy a 15 pitch prop to get this to where I need to be? I'm also looking for a little more hole shot for towing a skiier. Let me know what you guys think.

 

[solar7647]

Re: Force Prop help

Well every inch reduction in pitch is about 200-300 rpm increase, so as long as the new prop is the same manufacture and modle as the old you will see that increase in RPM, if you switch the make and model of prop you may not get those results. Also are you hitting WOT RPM when you are by your self? When you have a load on do you trim the motor up at all to bring the bow out of the water? This would help in getting the proper RPM. Are you sure that the extra gear and or people are not taking you past your wieght limit this would also cause the problem.

 

[Frank Acampora]

Re: Force Prop help

Read the model plate. The WOT range is 4500-5500 so at 4800 you are still within the recommended range. "Course, if you want a better hole shot, step down to a 15 pitch. The same prop in 15 pitch will most likely give 400 RPM more, although it is likely that the top speed will suffer a bit. If money is not critical, get a 17 pitch stainless. The Chrysler stainless runs about 200-400 RPM more than aluminum. However, if you get the Michigan stainless, it is cupped where the aluminum is not so RPM will remain about the same.

Just curious: Is the Vortex an open hub? If so, did you need to remove the anode behind the prop in order to fit the Vortex on properly? I have a 13 X 19 Vortex and the internal webs interfere with the anode. It must be modified or removed for the prop to slide all the way down onto the thrust collar.

 

[Bonstrosity]

Re: Force Prop help

I think there was a piece that was removed which might have been the anode. Once that was removed it fit perfectly. This was all done by the previous owner. I ordered another vortex prop w/ 15 pitch, I'll keep both so if I need more top end. Thanks for the help.