volvo penta 280 prop

[Afraser]

hi all

I have a bayliner 2850 command bridge 5.7 engine and 280 (recon leg). I checked the drive and its def right one 1.62 to 1

I have a 16 x 13 prop which I an told is the right prop for that boat. there is one guy that says hes got a 16 x 15 prop about 300hp and he can do about 30 knots. where the people with the 16 x 13 can do about 20 +

my problem is I can only get 10 knots at 4300 rpm but that's only about half throttle the engine doesn't seam to be working hard. Before I go out and spend a lot of money on a bigger prop I though I ask what you guys think

thanks
andrew

 

[jestor68]

Re: volvo penta 280 prop

I suggest that you verify the accuracy of your tachometer before doing anything; as those numbers don't compute.

You should be doing about 29 mph @ 4600 rpm(which is the maximum rpm for your motor).

With that gear ratio and pitch, that speed only computes to a little over 2000 rpm.

Or it might be that your prop's hub is shot(slipping) and causing that high rpm/low speed.

 

[Afraser]

Re: volvo penta 280 prop

if it helps I get 5.5 to 6 knots at 1500 rpm. I have hardly any weight onboard 2.8 kva genny a few tools myself and half tank of fuel (60 gal ish)

 

[jerryjerry05]

Re: volvo penta 280 prop

What kind of rpm's are getting?Max?
Sent you a PM.
Location?
Profile?
The aftermarket props don't always perform like the Volvo props.
Post a pic of your prop.

 

[Jayboat66]

Re: volvo penta 280 prop

My volvo penta is 4 cyl. And prop is 15x17 about 35 mph. At 4400 . Tell me the size of your boat.

 

[jestor68]

Re: volvo penta 280 prop

It's a 28 ft Bayliner Contessa; something like this one.

The prop's hub can work fine at lower power settings; and start slipping as the load increases. It would cause the rpm to increase while speed does not.

Since your boat's dry weight is a little over 8000 lbs, it's a pretty good load on the hub.

So my recommendation is as stated; verify the tach and check the prop's hub by simply putting another prop on it and see if it goes like it should.

If the boat has been in the water for a while, the bottom might be fouled with marine grown.

 

[Afraser]

Re: volvo penta 280 prop

hi all thank you for the replys/

It has the same hull as the one in the pic but its flybridge model. I have to get a new prop and see how it goes. It must be the hub slipping as I cant see any other reason why. bottoms clean just bin out to fit the new leg so was cleaned at the same time.