3.0 penta 1.97 drive wot hitting 5000!

[coreybechamp]

Hi everyone.

I just picked up my first boat! Yahoo. Dealer said it was stock.
Boat : 2007 ebbtide 180se about 2300lbs
Prop: 14.5x19
Drive: 1.97
3.0 penta motor with sx-a drive.

I hit 40mph at 5000rpm confirmed 60km on gps so speed is correctly reading or pretty close.

Motor says 4600rpm max.

Does it make sense? Is my tach off? Or am I over revving my penta.

What prop should be on it? Am I really doing damage? The tech also said the prop has cupping so from here I have learned that also can cause similar to high pitch over rev.

I just bought this dam thing now I am worried I was sold a bad combo. Opinions and help appreciated.

Thanks. Corey.

 

[fishrdan]

Not a huge problem, the old owners could have been running the boat loaded heavier or under propped it for water sports. Sounds like you need a 21P 3 blade prop,,, or a 20P 4 blade if you want to keep good hole shot.

 

[Sea Rider]

If combo has a good hole shot stay with that prop, bear in mind that as soon you start adding 1-2 more passengers max rpm will drop acccordiingly. If boating solo while lightly loaded watch tach as not to over rev more than stated max wot numbers. + 400 rpm is not a wow number to be afraid of. Have 600 rpm wot excess which can control adding 1-2 more passengers or throttling less when boating solo.

Happy Boating

 

[coreybechamp]

so.. i can work with it. From my simple brain please let me know if i am right. I have more HP/Torque to over rev the prop, that should be used in a better or more efficient way.. can i not put on a "bigger/more pitch" to allow me to go faster and better hole shot without over reving?
the current prop spins to fast based on the load. Please keep in mind i have filled the boat with people and gas and still over reved to 4900. people and load dont seem to take out more than 200.. let me now your thinking.

 

[steelespike]

The simple solution is to go to a 21" pitch it will slow your hole shot a little but may add some speed.
A 20" 4 blade should help retain your hole shot and get your rpm in check.
The 4 blade has a reputation for hole shot, ability to stay on plane,smooth operation and good responce around the dock.
60 km calculates to 37.8.mph this indicates 17% slip acceptable though a little high.
​ If we assume a slightly more normal slip of 12% and 37.8 mph we get a more acceptable 4815 rpm.
A cupped prop you mentioned would test like a 1" higher pitch So would tend to calculate to a lower still rpm.
4574 assuming 12% slip and 37.8 mph.
If you want to check your tach you may be able to borrow a shop tach.

 

[Scott Danforth]

I would verify your tach

 

[Stingray185GXi]

I agree that you should verify your tach, if it's accurate than I would put on a 4 blade 14x21 pitch prop.