I was told that at WOT I should be getting somewhere between 4300 & 4700 rpm. Currently I'm getting around 5k I'm thinking this is a prop issue. Where can I find what pitch the stock prop was? Currently it's got a 15" x 17p on it
I was told that at WOT I should be getting somewhere between 4300 & 4700 rpm. Currently I'm getting around 5k I'm thinking this is a prop issue. Where can I find what pitch the stock prop was? Currently it's got a 15" x 17p on it
That's a 1996 5.7L (not LX)... Max rev WOT should be 4200-4600... If you're getting over 5000, then change the prop to one with a pitch of 19"... That should bring it down by about 400 rpm... Putting you very nicely at the top end of the rev range... Perfect!!! (doesn't matter if you're a 100 or so over BTW), unless you're water skiing, then you need to be a prop under for pulling, in which case you have the right prop now.... There is no 'stock' prop on boats... The right prop is the one that allows the engine to reach to WOT max revs recommended by the manufacturer, in that particular boat, with that particular load... (get the picture?)
Boat info is good too That way we can tell if something seems out of whack. Tach has to be right. Very common that they aren't. My guess is that it is right as a 17 seems low as well.
The Mercury Marine web site has the best prop selector I have found. It's an easy five step process to find out what prop is best for your boat. You'll need accurate weights and your gear ratio. The rest is point and click.
The best (only correct) way to determine the right propeller is to actually put a propeller on the boat and try it. Websites and calculators only get you to a starting point, which BTW, you already have. (5,000rpm with a 17" prop)...
That way we can tell if something seems out of whack. Tach has to be right. Very common that they aren't. My guess is that it is right as a 17 seems low as well.