Prop Question

[JRuggiero]

Hi - on a recently purchased boat/motor...<br /><br />1965 Glasspar 16ft w/1971 Evinrude 60hp<br /><br />The previous owner had replaced a worn looking prop prior to my purchase. The old prop was a 3 blade 13 3/8 x 17. He put on a 4 blade 12.8 x 17<br /><br />I don't think this is a big difference, as the 17 stayed the same, but just wanted some imput. The boat's only doing about 30 now (I know the carbs need some adjusting, they were obviously rebuilt recently, but if you some some of the other do-it-yourself things on this boat...) and that seems slow for this combo. I don't have a good tach reading, rectifier did a doosey on it, just floats up to 7000 now just above idle. Boat gets to max speed quickly, but at WOT (I believe in the 4800-5200 range by sound) I don't get top speed!<br /><br />Any advice is appriciated - thanks!

 

[ob]

Re: Prop Question

You really need to give us an accurate tach reading for us to advise.Off hand I'd say that a 60 hp pushing the 16 ft.boat you have with a 17" pitch prop may be just a tad steep in pitch.That's just a blind guess though and is really useless in final selection without knowing the WOT rpms.Good luck.

 

[Reel Appeal]

Re: Prop Question

You may be sacrificing a little speed using the 4 blade prop.Four blades are good for hole shots and quick acceleration.I would consider the original 3 blade size or a higher pitch 3 blade.The higher pitch may or may not help.If its too much prop it will "slip" or cavitate,maybe overheat the motor.Best way to increase speed is to increase horsepower.Do not exceed recommended horsepower rating.Try to borrow some test props and see which size/combo works best.Marina's/boatyards sometimes will lend test props if it makes a new $sale.