Prop Options for DF90

My current prop came with a couple of chunks missing and I have it repaired but I am now looking at replacing it.

I have an 2011 DF90 on a 5m Seafarer (600kg) which has a rev range between 5300-6300. The ali prop is 3x14x17 and pushes me at 33 knots @ 6200rpm at WOT and cruises at around 22knots @ 4500rpm.

I'd like to improve my crusing speeds and I know that increasing the pitch will give me lower revs reducing my hole shot and going to a 4 blade will improve my hole shot, crusing speed and handling but will reduce my top end speed. Another option thrown my way has been to slightly decrease the prop diameter and increase the pitch which would circumvent some of the RPM loss but I would lose some trim which doesn't bother me as much as she's pretty rear heavy and I like to get her nose down most the time.

I plan on doing a bit of trolling around reef for tailor and salmon and heading upriver in snag country with the kids etc so shying away from a SS prop in case I clip something.

I would like to see if anyone has gone down the same path and can give me some feedback.

 

____________________________________________________________________________

Officially off the Pies bandwagon


Posts: 812

Date Joined: 09/10/06

 Are those numbers with your

Wed, 2016-08-31 12:23

 Are those numbers with your usual load for a days fishing or lite. Your numbers are on the mark. Have same motor and prop on a 5.3 ali. When lite l touch the rev limiter but once loaded lm at 6000. Had a 19" ali and once loaded the rpm at wot dropped to much 5250. These things like to be at the top of the rev range with normal load. If you're got money to burn go a SS prop but at $600 not worth it.

Jackfrost80's picture

Posts: 8050

Date Joined: 07/05/12

Cheers mate. Came in from

Wed, 2016-08-31 14:06

Cheers mate. Came in from Forrest Beach to Busso with 3 on board and fish in the esky one day sitting on 6200 and 32kn the whole way. She loved it haha.

Seeing as she uses 22L of petrol for a 28 mile trip I guess I could push her a little harder than 4500 for longer trips

____________________________________________________________________________

Officially off the Pies bandwagon

Posts: 812

Date Joined: 09/10/06

 Ok so if your pulling 6200

Wed, 2016-08-31 19:12

 Ok so if your pulling 6200 with a that heavy load you probably could turn a 19 and still be in the 5900/6000 rpm range. May be worth a try. The ali props arent that expensive 

Posts: 23

Date Joined: 01/01/70

 I have a df80a on a 490

Wed, 2016-08-31 15:54

 I have a df80a on a 490 (5.13m) quintrex and my cruise is 43kmh @ 4500rpm and wot is 53kmh (5800rpm, I should get close to 6000rpm once it's done more hours) and I'm running a 3x13.875x15 suzuki ally prop. I don't know if that's any help to you if you were thinking of running a simular size prop to mine. Those speeds were with two people, fishing gear & a 60l esky full of ice. The max rpm for the 80 is 6000...

Sorry just reread and if you were going to a 15" prop you were going to increase pitch... with the fuel and speed your getting at your rpms sounds like it's spot on. 

North Coast Marine's picture

Posts: 74

Date Joined: 23/05/16

I would keep my eye out for a

Wed, 2016-08-31 16:45

I would keep my eye out for a stainless prop, better grip, more designs to chose from, minor dents can be hammered out, more efficient and they look better haha

____________________________________________________________________________

 

 

   

Jackfrost80's picture

Posts: 8050

Date Joined: 07/05/12

 Only problem mate is you've

Wed, 2016-08-31 20:47

 Only problem mate is you've seen where my prop sits on my property would be very easy for someone to sneak up to take off a nice shiny SS prop

____________________________________________________________________________

Officially off the Pies bandwagon

Krusty's picture

Posts: 714

Date Joined: 27/11/15

 You can always take it off

Thu, 2016-09-01 18:27

 You can always take it off yourself.....with the tools at hand you could have it off in under 15sec 

____________________________________________________________________________

 

My fishing spots are so secret........... even the fish don't know where they are !!

Jackfrost80's picture

Posts: 8050

Date Joined: 07/05/12

 Haha great thought... won't

Thu, 2016-09-01 19:03

 Haha great thought... won't happen

____________________________________________________________________________

Officially off the Pies bandwagon

Krusty's picture

Posts: 714

Date Joined: 27/11/15

Yea ..... I hear ya !!

Thu, 2016-09-01 19:10

Yea ..... I hear ya !!

____________________________________________________________________________

 

My fishing spots are so secret........... even the fish don't know where they are !!

Posts: 5745

Date Joined: 18/01/12

 Solas tell me they dont

Thu, 2016-09-01 18:51

 Solas tell me they dont recommend 4 blades under 150hp from memory

You should be propped for the maximum normal load you will carry, and ALWAYS better to be under propped than over.

I wouldnt bother with SS either, the benefit not worth the cost (including theft)

Try a 19, someone here should have one to lend?
I just got back from Perth, could have brought down a 21 to try.
But if you have to buy a cheap 19 then dont want it, I'll buy it off you as I want one as a spare for my boat.

____________________________________________________________________________

 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.