Propeller question

[AComo]

Hey all!
1988 Baretta success 200, aq131d 275 outdrive.
compression across all cylinders 170+
idles great, runs great.

Manual states for the aq131 Wot is 5k rpm.

the current prop is a Volvo penta 3 blade aluminum prop. 14x19 LH rotation. That is kinda dinged up. Well bent edges. Cracked edges. So probably pretty bad.

Running the engine in neutral, and manual revving the engine at the carb I can get the rpms up to wherever on the tach. Since there is no load on the motor. *thought it was a tachometer issue at first.

running wot on the lake tachometer doesent go above 3k.
Is the damaged prop causing the significant decrease in rpm? 2k??

or is this not the factory propeller and precious owner changed diameter or pitch ?

while it’s pegged for a few seconds on the lake at 3k rpm I’m going about 35mph with me and the wife on board. Confirmed with gps. Which is fine with me and it gets up and goes pretty well. Before I buy a new prop to put on it. Should I replace with the same size one that’s on? Or is something better.

thanks!!!!

 

[Scott Danforth]

first, your motor would probably run to 5000 RPM in neutral running on 1 cylinder. it takes literally a few drops of fuel.....doing that doesnt prove anything.

to run to 5000 RPM under load requires many many ounces of fuel.

look at your carb

and also look at your prop, yes, a dinged up prop will effectively load the engine without providing any thrust

 

[AComo]

first, your motor would probably run to 5000 RPM in neutral running on 1 cylinder. it takes literally a few drops of fuel.....doing that doesnt prove anything.

to run to 5000 RPM under load requires many many ounces of fuel.

look at your carb

and also look at your prop, yes, a dinged up prop will effectively load the engine without providing any thrust

Hey thanks for the reply. I only played with it in neutral to see if it was the tachometer not going over 3k.

the carb seems to be running well. Cleaned and rebuilt a few weeks ago. Butterfly valve opens completely at full throttle on the lever. No rough idle. No chugging. No backfire. It’s also got new plugs, wires, coil. Cleaned fuel tank and blew out uptake hose in tank. New fuel pump. New fuel filter. I thought too it may be a carb problem at first. But wot &3200 rpms I’m @35mph. That’s why I thought it was the crapped prop

 

[QBhoy]

Is that an outdrive that used to be the port outdrive on a twin engine boat previously ?

 

[captmello]

I would use a different tach to make sure the one in the boat is working. Your numbers don't add up. Post a pic of your boat if you can, I've got one just like it, but with a V8.