OK! 14 foot banshee with a Chrysler 130. Good combination. I had a 14 foot flat bottom with a Force 125 and she did 60MPH at 5900 RPM. I was using a Chrysler Stainless cleaver prop, 12 1/2 X .21. I have also used other props and even with a lower RPM, speed still stayed around 60
You, my friend are very limited on prop selection because those 18 spline props are no longer available new. You must find them on the auctions. You could look around for a Bronze prop but I doubt you will find stainless. Aluminum is regressive. If you want performance, you really need to find a couple of bronze props
21 pitch on a boat that size is about correct but to get RPM up a little you must raise the engine on the transom a bit. Anti-ventilation plate about 1 inch above the bottom would be about correct.
NOW, for some background so you know what you are dealing with: Chrysler rated their engines at the powerhead until about 1982. That means that in the water, you are getting about 110- 115 horsepower. Later Chrysler and Force engines were rated at the prop so horsepower rating is more true. ADDITIONALLY: The two piece lower unit and thrust pin 18 spline prop is about 1 inch longer than the one piece lower and less efficient. Thus, the net effect is that the engine performs like a smaller one
If you are satisfied with performance, you can leave the engine like it is. With a little tweaking you should be able to get a little more speed.
IF, on the other hand, you are unhappy with performance, you can swap the complete powerhead onto a one piece midleg and lower unit. The advantage will be: 1. At least a 3 MPH increase and 2. A much betted selection of props , again leading to a higher top speed. This mod is not particularly difficult but it will take a complete weekend day.
The button valves are brass valves in the top body of the fuel pump that check the flow of fuel to keep it in one direction. To check them, clean the body well and alternately blow and suck on each valve. If they pass air freely in one direction and seal (relatively speaking) in the other direction, they are good. The seal does not need to be perfect, they can pass a little air and still function correctly when wet with fuel.
1 1/4 turns out is actually a little rich but will certainly do no harm and is way better for the engine than a too lean condition. It certainly sounds like the engine is running out of fuel at the top end and continued use like this may be bad for it. I suggest you do not go over 1/2 throttle until you rebuild the fuel pump.
