Change prop Mariner 60HP 03?

Marcus@globalpl · 06 June 2006, 09:12

I managed to get my mits on a 1 1/2 year old Yachtline 480 at a "reasonable" price. So far really pleased with it. She came with a 2003 model Mariner 60 EFI. Only issue I would like to sort is that the motor hits and goes thru max RPM (6000) very easily and cavitates on tight turns. I would like to change the prop, which I think is standard to get a better top end (currently 30kts GPS) any ideas what size/pitch?

Turbodiesel · 09 June 2006, 22:15

What prop is on it at the moment?

antiqueboy · 12 June 2006, 21:38

i have a similar boat medline 1 with a 65hp suzuki 2 stroke engine, max revs 5600 i only hit 5000,25 knots, and slow to take off,my prop is a re con alliminium 11 1/2 inch and 15 pitch, how does this compare to yours as i keep thinking it is wrong but i do not know if the pitch is wrong, the size, or the whole thing or if i am just hoping to get more out of a small engine,any ideas

ADS · 12 June 2006, 21:55

Quote:

Originally Posted by Marcus@globalpl

I managed to get my mits on a 1 1/2 year old Yachtline 480 at a "reasonable" price. So far really pleased with it. She came with a 2003 model Mariner 60 EFI. Only issue I would like to sort is that the motor hits and goes thru max RPM (6000) very easily and cavitates on tight turns. I would like to change the prop, which I think is standard to get a better top end (currently 30kts GPS) any ideas what size/pitch?

If its exceeding the max operating rpm, which it must be if its hitting 6000rpm, you need to go up in pitch. Try and find out what the pitch of the current prop is, should be engraved on there somewhere.

Quote:

Originally Posted by antiqueboy

i have a similar boat medline 1 with a 65hp suzuki 2 stroke engine, max revs 5600 i only hit 5000,25 knots, and slow to take off,my prop is a re con alliminium 11 1/2 inch and 15 pitch, how does this compare to yours as i keep thinking it is wrong but i do not know if the pitch is wrong, the size, or the whole thing or if i am just hoping to get more out of a small engine,any ideas

Sounds like you need to find a few more revs, probably best to borrow a 13"/ 14" pitch prop. You should see more than 25knots, how big is a med 1?

antiqueboy · 12 June 2006, 22:07

4.8 meters deep v 2 adults 3 kids 40l of fuel+ normal kit

Nos4r2 · 12 June 2006, 22:09

Have you tried using it solo?

My sr4 goes like stink solo or 2 up with a 14" prop on a 50hp, but put an extra person aboard and can't get over 25 knots. With a 13" and 3 people it hits 33 knots.

antiqueboy · 12 June 2006, 22:20

i would love that chance to come up, but the wife has taken to boating, my fault for letting her do the pb 2 course with me, one son who never leaves our side, the wife has booked up most weekends with friends to take out,whats it like solo? i guess i will never know

Nos4r2 · 12 June 2006, 22:32

You only need try it for half an hour.....tell her it's important engine diagnostics and it might save you some money on fuel....

antiqueboy · 12 June 2006, 22:50

wife wants to go to the witterings next sunday so maybe i could leave her for a while, could be tuesday buy the time she walks home hmmmm.....

Nos4r2 · 12 June 2006, 22:54

Seriously though-if she's done the PB2 she should understand the need to have the boat at its optimum for the purpose it's used for. If you can't get a hell of a lot more speed out of it solo then it'd be time to have a look at the engine to make sure it's ok.

OR....you could always buy a propulse variable pitch prop and experiment?

www.propulse.se

antiqueboy · 12 June 2006, 23:17

thanks for that never heard of them do you know anyone who has tried/uses them?i will try to get out on my own the recommended top end rev range is 5000/5600, so i am right at the bottom of the scale and as i only have a handheld gps,and the boats speedo is cra! i have not used it a lot to test speed so i will be do a few more tests i assume most people talk speed over land in these forums?

Nos4r2 · 12 June 2006, 23:20

Noddy's got one- he seems to think it's ok.

I guess it's a cheap way of finding out what pitch you need?

It's kinda a mixture of MPH and Knots on here, depending on what system people are using.

If it's any help 1 knot = 1.15078030303 mph

Marcus@globalpl · 14 June 2006, 09:45

The number is 48 816702A40 12P which I presume is a 12" prop does it sound a bit small?

Thx Marcus

ADS · 14 June 2006, 11:47

Quote:

Originally Posted by Marcus@globalpl

The number is 48 816702A40 12P which I presume is a 12" prop does it sound a bit small?

Thx Marcus

yes.
My 4m Avon with 40HP 2stroke ran a 13" ally prop and that used to scream, accelerated like a Enzo, although the top end was alittle dissappointing, really needed a 14" or a 15".
My current boat has a 70HP Tohatsu and a 17"prop, we tried several props and this one is the best match of acceleration and topend and at WOT sits nicely in the middle of the prescribed max rpm range.
I would try and borrow a 14" prop and see how you get on.

Marcus@globalpl · 14 June 2006, 14:24

Thx ADS.... Im going to try out a 15 pitch will let you know how I get on. Got loads of advice from Steve at Barrus...top geezer!

Marcus@globalpl · 27 June 2006, 11:54

Hi

Put a 10.125 / 15" prop on.
Now cruises at 23kts (GPS) against 18 before.
Top end up to 32 from 29/30.

Engine hits max of 5600 rpm....so I think ive got the right one!