Re: 15 pitch vs 16 need help
You need to read the sticky at the top of this forum that explains what information is needed when considering a prop change. You've given us absolutely nothing to go on. The best prop for your boat is one that allows the engine to rev at or near the top of the engine manufacturers wide open throttle RPM range with what you consider an average load. You have a tach on your boat. What does it read at wide open throttle? If the engine can't reach the upper end of the manufacturers rpm band, you have a tired engine or the prop already has too much pitch and the engine is lugging. If the prop you have does indeed perform as it is supposed to then you don't need, nor will there be much of an advantage in changing pitch. If you go with more pitch under those circumstances you risk increasing fuel consumption due to engine lugging, loss of hole shot, and loss of top speed. So until you do some wide open throttle runs noting speed and engine rpm with your current prop, we don't have a clue if it will help or hurt. The long and short of this is that you can't simply bolt on a prop with more blades and more pitch and expect to make a rocket out of the boat. The engine must have the power to actually twist that prop.
Everyone is trying to help you, but too many are at a loss and need certain data for each comment. Silvertip said it quickly and his should have been Followed: this list from the stickies at the top of the prop forum page:
ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight
We reaelize you will not be able to retreive the data until ice melts (waters warm), but be prepared with this list on board and bring all the data posible.
#4 talks about average load readings. If your test run is not average loaded, then tell the differences in load on test day.
There are WAGs, SWAGs, and then there is expert advice. Test with the 15" pitch prop you have and get back to us. Take a laptop to the dock and upload the information quickly! you may well receive advice for making other tests or performing a modified run. The best possible result will be your ability to purchase a new prop from expert advice while you are still at the marina and then have immediate testing/results of the new prop.
Good Luck! let us know when your test date comes!!
we want to help
