selecting a prop

Question
I have a 1988 24' Kennedy pontoon w/a 1994 40 hp Johnson. It has a 11.75x17 prop on it  now it doesn't seam to be reving up all the way but I don't have a tach. what size prop do you recommend? What do you think is the red line of that motor. Also what do you think is the approx weight of that combo?

Answer
Hi Matt...Thanks for selecting the undersigned to respond to your question.

I'm not a mechanic, but you don't need a tach to check the performance of your prop. Your top end speed (wide open throttle) will give you the answer. It's quite unusual that one minute everything was okay, then the next minute the engine is running sluggish, but I'm presuming the prop is undamaged. Did you check the prop shaft for any obstructions like fishing line, etc? Is the prop securely attached or loose? Are the vessel's pontoons taking on water?

For engine specifications, go online to the manufacturer's website. Make sure you have the model and serial number of your engine handy.

Safe Boating
Ron