Why am i getting prop slip !!!!!!

[Shifflett115]

Hi everyone , i have a 1985 bayliner with a force 150 on it , i have a 13 1/2 by 17 pitch prop , my wot rpms are 5500 to 5600 rpms but i am getting prop slip out of the hole , why is that , If i put a 14 BY 19 Pitch quicksilver prop on it i get no slip out of the hole but my wot rpms are way down . I pit the motor on last fall and just want to prop it right , we do alot of water sports off the boat also , thank you for any info

 

[H20Rat]

\What you are describing isn't prop slip, it is most likely ventilation. If it is intentional with a vented prop, that generally is a good thing. Basically works like a torque converter in a car and lets your engine get up to a decent rpm where it can build horsepower.

 

[Sea Rider]

If it's an outboard engine powering a Bayliner, could have a spun hub, OB sits to high on transom, is incorrectly trimmed or undergoing a tri combo of mentioned issues.

Happy Boating

 

[Redfred1]

What size Bayliner; please?

 

[Starcraft5834]

Id look at the prop as Sea Rider mentioned, see if your hub is slipping.... if you have a hub that is............

 

[Shifflett115]

my boat is 19 ft , the hub is good , once it planes off its fine , just slips getting on plane

 

[Shifflett115]

yes its an outboard , the motor is mounted correctly on the boat also

 

[Shifflett115]

the prop i am using is not ventilated either

 

[SkiDad]

Some of the force props are better than others. I like the ones with round ears better than the semi-cleaver style. Is your engine dual exhaust?

 

[Shifflett115]

Yes it is, I am going to try a 13 / 19 pitch mercury aluminum this weekend and see how it goes

 

[fhhuber]

Ventilation/cavitation (probably cavitation) from having enough horsepower to drive the prop faster than it can move water.

Most of the time a correctly sized prop can be spun,at an rpm which is "beating the water into submission) when you are doing the hole shot...

Just don't apply quite as much throttle and SOMETIMES you can avoid the worst of it and jump out of the hole faster. Its kind of like spinning the tires on slick road when leaving s stop sign.

************************

The above assumes the prop is not spinning on the hub... This can also show up initially just during hard acceleration. It never gets better.

Paint a line across the hub clear across the rubber insert and on the metal each side of the rubber (include the nut) . Do your hard acceleration and then stop and check the line. If the line is not still continuous you need the hub repaired or a new prop.

http://forums.iboats.com/filedata/fetch?id=6940280

 

[steelespike]

my boat is 19 ft , the hub is good , once it planes off its fine , just slips getting on plane

Is this a bow rider or cuddy?

 

[ufm82]

What kind of prop, is it cupped, is it in good condition, stainless or aluminum, etc. You may have the right pitch but need cupped blades. You may have the wrong pitch and are blowing out the prop. Are you trimmed fully down at take-off? Is your weight distributed fairly well. Lots of variables here.

 

[Shifflett115]

Its a cuddy, yes the motor is pretty much all the way down on take off, I had a 13 1/2 by 17 pitch semi cleaver aluminum on it, Im going to try a 13 by 19 pitch aluminum on it and see what happens, yes the weight is distributed correctly, I have tried a 14 by 19 pitch on it before , no slip but my wot rpns we're down