Help with New Engine for Zodiac Pro530

[Keepitwildak]

Thanks Phil! I was hoping you might get a bit more efficiency out of it considering the hull has some decent displacement as compared to say a Searider. What year is your 530? Mine is a 1990. I will take a photos of mine this evening. I believe mine has the lip at the top of the transom. After looking at your hull from the pictures in the thread where you were working on it, our appear to be identical. I would imagine the thicker the transom returns, ect would mean it should be able to handle a bit more stress. Cgoing mentioned installing tie bars to stiffin the transom like a Searider has.

How many hours do you have on your 115 now?

[Phil M]

Mine is an 88 i think nut will check. The opd engine may have been 88 and the hull a little older. I figured the low top speed and lowish efficiency (although it isn't bad at all really) wS due to the extra weted surface of the reverse chines and the relatively wide beam for a boat of that length. The seariders are a good foot narrower on deck hence i prefer the 530 for diving.

You probably saw in the build thread but i did strengthen the transom base at either side. Also muline does not have the lip but the full thickness edge returns, so is a very strong shape. Sadly means i cant fit an aux engine though.

The engine has only clocked about 22 hours. Last year was very windy and most of the time it was just too rough for the hull. The boat coped but the passengers not so. Its a good hull but a bit of a hard ride in the close chop we get in the estuary.

Phil M

[Phil M]

As promised, the photo below is marked up with the crack locations, prior to repair.



This one shows the transom detail on the earlier models. I checked the plate and it is from 07/88.



Phil M

[jonp]

I can't believe we are 3 pages in on this conversation and no mention of propping or engine setup.

I own a 550 pro with a Yamaha f70 and have no problems reaching 6000 rpm 32 knots with 3 divers and 6 tanks etc. My engine is now mounted 2 holes higher than the dealers had set the boat up from new and I've changed from a 13x15 inch alloy prop to a 13 3/4 x 13 Solas stainless.

With light loads I can rev out to 6200 for a top speed of 35 knots and have a very economical ride at 4500 rpm on 23 knots. Nothing I hate more when diving than smelling 2 stroke fumes pre dive, which is why I will never own another 2 stroke again.

The Yam f70 is the lightest in its class and pairs very well with the 550 when setup correctly. Over here there aren't to many days where you could use more power due to the strong winds that build each day from rising temps on land. More power maybe fun for calmer waters but in the wrong hands on these lightweight boats can be dangerouse.

Jon

[Keepitwildak]

JonP, what is the hull shape of the Pro 550 that you own? Could you attach a photo by chance?

I am typically running 300-500 kilometers a weekend and a lot of times I am able to find near calm waters. With payload of 4 regular sized guys and gear, I'd like to have my economical cruise speed be somewhat higher (maybe 26-30kts I'm hoping) if I go with a 115hp outboard.

What is your economical speed with 3 divers and tanks? What is the burn rate at that speed on flat water?

Cheers,
LP

[jonp]

Mine is a 2014 550 tour and I believe the strakes are slightly different on these newer models giving more lift. I also run quite long distances but these are more on the fishing side rather than diving. Ive done over 200 hrs in 7 months so far with this boat and also had another F70 on another boat Ive I sold recently. The boat that I owned with the 90 suzuki is also now sold (to many toys!!).

Ive owned many engines over the years and these Yam 70 4strokes and the latest 90 Suzuki's have been my favourite.

Jon









Older style hull





My best cruise is around 4500-4700 with three divers where we average 3.5km per litre on 40- kmh, loading seems to make very little difference. As you state more power would defiantly be better for you considering the conditions and distance you are covering, so a 90 would be minimum. The new Yam 90 4 stroke recently launched should be well worth a look in my opinion.http://www.yamaha-motor.com.au/produ...d-power/16-f90

Im just heading away for a few days so wont be able to answer any questions for a week.

Cheers Jon

[Keepitwildak]

JonP,

That's a beautiful RIB indeed. By chance have you kept any records of speed/burn rates at known load in calm water? My Pro 530 is not near a deep a V and has large reverse chines which should provide a lot of displacement (in hopes of better economy).

Cheers,
LP

[jonp]

This may be of more help, just put in your boat size and you can find all sorts of reports on different engine fuel burn-speed etc info (all Yamaha though but should be similar for most brands) Outboard Performance, Performance Bulletins | Yamaha Outboards

By the way Ive just altered the above so now there is a little more burn speed info. In regards to calm water I get better performance with a little chop as the air under the hull reduces drag, I can normally pick up 5 kmh more speed with a little chop at the 4500-4700 compared to flat water.

Jon

[office888]

Originally Posted by jonp

I own a 550 pro with a Yamaha f70 and have no problems reaching 6000 rpm 32 knots with 3 divers and 6 tanks etc. My engine is now mounted 2 holes higher than the dealers had set the boat up from new and I've changed from a 13x15 inch alloy prop to a 13 3/4 x 13 Solas stainless.

My friends Pro 550
4 divers, cold water kit (drysuits)
8 tanks
Mercury 70hp, 13 pitch aluminum prop, 5800 rpm or so was about 27 mph.

For dive boats, I strongly encourage rigging at the max engine rating.

The downside is that the 5.5m is a fairly short hull, so in rough conditions, you're not going to need the power anyways because you're going to have to throttle back. Offshore you could probably get away with a smaller outboard because of that. Great Lakes region, definitely go with max hp.

[Keepitwildak]

Office888,

Thanks for the info. Do you have any more performance specs, maybe from your own RIB? Looks like you run a 5m with a Merc 100hp?

I'm always interested.

Cheers,
LP

[office888]

Originally Posted by Keepitwildak

Office888,

Thanks for the info. Do you have any more performance specs, maybe from your own RIB? Looks like you run a 5m with a Merc 100hp?

I'm always interested.

Cheers,
LP

1998 Avon Diveboat 560 (wide beam)
1999 Mercury 100hp 2st 2+2cyl (rough shape)
Powertech WBH3 14x14 prop (wide blade, workboat prop)
Fouled hull

Did about 28 mph @ 5200rpm. Planed quickly though, even with 5 people and 2 dogs onboard.

[br1anuk]

Suzuki DF90.

[cornishcoote]

Hi

I would like some advice around what prop on my Zodiac Pro 550 which has a 2003 Honda 75hp. It currently has a Sola's Stainless Steel 13" x 17 rated prop.

The engines Wot is 4500 - 5500 rpm, but flat out I'm at 5600rpm doing about 30 - 32mph. I wonder if the last owner swap the prop as he was over 6ft and used to wakeboard behind it.

I want to know if I swap the prop will I get better cruising ability/ fuel economy? Maybe better top speed?

Any advice appreciated on what prop to swap it to?

[jonp]

Originally Posted by cornishcoote

Hi

I would like some advice around what prop on my Zodiac Pro 550 which has a 2003 Honda 75hp. It currently has a Sola's Stainless Steel 13" x 17 rated prop.

The engines Wot is 4500 - 5500 rpm, but flat out I'm at 5600rpm doing about 30 - 32mph. I wonder if the last owner swap the prop as he was over 6ft and used to wakeboard behind it.

I want to know if I swap the prop will I get better cruising ability/ fuel economy? Maybe better top speed?

Any advice appreciated on what prop to swap it to?

What should that motor rev out to at max? I'm running a 13x13 stainless Solas with my yamf70 to get 6100 max rpm. I would of thought a 15 would be better for yours.

By the way I have the 550 pri tour latest model.

Jon

[Char]

Run a hurricane 530 with a yam F70 well paired. Fuel sipper ....zips around with a load. Planes easy with a load. Plated on the transom for 75 replaced the original 2 cycle 75 with a 70very pleased with the match

[cornishcoote]

Thanks for the reply. 5500 is max rpm looking at manual. Optimum WOT is anywhere between 4500 and 5500 rpm. I guess I want to be near top end of that range. I'm thinking I could drop down to either a 15 or maybe a thirteen like you.

[cornishcoote]

Also do you think my speed is about right in comparison to your Jon?