Help with New Engine for Zodiac Pro530

Phil M · 19 March 2014, 21:42

I had a chat with the workshop today and they advised my old Mariner 75 is going to need a re-bore if it is to be of any reliable use and at just under 30 years old, I'm not sure its worth it. So I find myself looking for a replacement engine.

The old Mariner ran ok, till it died, but was smokey, smelly and thirsty and I fancy something a lot newer, cleaner, quieter and more economical, oh and bigger

.

I've looked at the second hand market and can't justify the cost for an engine of the right age with potentially unknown issues, when new ones are not that much more, so I'm thinking new is the way forward.

The issue I have is that the boat is old and although rated to 120hp, has no max transom load on it. As engines have got a lot heavier, I have no idea what is safe to hang on the back, particularly as I have a 25kg aux on there too. The best guess I have is the mariner 115 of that era was about 160kg. I can't find a contact for Zodiac either to ask them for advice, as they direct you to the dealer network.

I use the boat as a family toy, fishing boat and heavily loaded dive boat. The 75 was quick with just me in but struggled with divers. I'd like to go with a bigger engine but that puts the weight up even more. I also suspect 115hp might be a bit too much for the hull. To complicate it further, I'm planning on replacing the hull in a few years with something like an XS545 or 585. The 545 has a max hp of 100, which would suit the current hull, but means 4 stroke and heavier (honda 100 is 163kg). A 90 would be fine for the 530 and the 545, but possibly too small for a 585, although much lighter (90TLDi is 143kg)

So, after all that, what engines do any of you other 530 owners have? How do they handle (top speed, chine walking, quick on the plane etc.)?

Any thoughts on what weight I can safely hang on the back?

And finally, any thought on how well an XS 585 or similar would go on a 90 or 100 motor?

Based on weights, price, local dealers etc, if I go 90hp, then its the TLDi, 100 is probably the new honda (expensive but quite light and very nice!) and 115 would probably be an Opti or TLDI.

Thanks,

Phil

Phil M · 20 March 2014, 12:34

Anybody?

Phil M · 20 March 2014, 13:55

The workshop has been back on the phone. The old girl lives after all, so please ignore this thread.

Phil

J.W.W. · 26 March 2014, 14:09

Lucky you

!
When have to replace in the future, dont't exceed the max.hp with this one!
Have seen a couple of them which complete ripped apart with overpower..
115 is a nice engine, but a 90 would do nice too..

Dan Gurney · 26 March 2014, 15:50

For what it's worth, my 20 year old Humber Attaque was plated for 150hp

When I contacted Humber they said that the OP 5.3 which is basicaly the same boat, is now rated for a 90hp four stroke and a weight of 170kilos.

Dunno exactly what this means for you but might be of interest.

On the XS question: the RYA centre at cumbrae run XS600 (I think) with Yam 115s on which run fine 4+ up (the instructors use it for their commute over from Largs Marina). Also Doug Stormforce on here has his XS600 up for say with a 115 Merc 4st. That was a school boat so I would guess used to running 4 up at least. Dunno how the 600 hull differs from the 585 though.

Phil M · 10 July 2014, 17:32

Thread resurrection time!

I've sold the old engine and am once again in the engine size dilemma. So, same questions again. What do people power their 530's with? I've narrowed my choices to a 90 tohatsu (light, well priced), honda 100 (light for a 100) or a 115 opti (light for a 115 and well priced). Suzi's, evinrude and yam all mean long drives for servicing (4hr min round trip) so are out of the picture.

Any thoughts, advice or experiences welcome!

Phil M

tworotorturbo · 11 July 2014, 14:06

I had a Honda 90 on my Zodiac 530. It felt perfect for the boat. I usually had three people and I didn't feel like I needed more power. It planed quickly but the boat console/fuel tank was setup nicely and was balanced well. Theres a drone video of my 530 somewhere on ribnet.

cgoing · 12 July 2014, 17:20

I have a 75 ETEC on my pro 530. Personally I would love more power however the engines today are much heavier than when the boat was originally built in 1989. I have also rebuilt the entire boat including new stringers, underdeck 25 gallon fuel tank and a glassed
in a bow locker. When choosing a motor I found the specs from mercury/ mariner in 1989 . The 115 hp from 1989 weighs less than my 2011 75hp ETEC. Without totally reconstructing the entire transom I choose to stay lower on HP rather than over stress the boat. I also added Searider styled transom supports. The boat does 31 mph flat out with my wife and two kids on board. Good enough for a family boat for now.

Phil M · 15 July 2014, 12:12

Thanks for the responses.

Weight is my main concern. I've done some digging through various threads and peoples signatures and have found the following 530 hull/engine combinations. I should also stress that my boat is the old style transom with the hollow returns on the outer edges. Sort of a /---\ shape, viewed from above and behind and may differ in load capacity than the newer design. Anyway, I've found the following engines have been used.

Evinrude 120 V4 - 166kg (365lb)
Twin mariner 60 clamshells - I guess about 90kg each so 180kg (396lb)
Mariner 75 clamshell - 127kg (280lb)
Merc 115 2st (1991) - 148kg (326lb)
Merc 115 4st (2001ish) - 176kg (386lb)
Honda 90 - 163kg (358lb) lightest since introduced.

Based on the above, I think I'm comfortable putting the honda 100 on
(as its the same weight as the 90) without overloading the transom. I don't have to use full throttle all of the time but it will give me a little more scope if I replace the hull. Just need to find the best price I can now.....

Phil M

Captain Pepe · 11 January 2015, 18:45

Hi

What the top speed on youre 90?

I will like to buy a Zodiac Bayrunner 550 with a 90

Phil M · 20 January 2016, 12:49

I know its an old thread but I just thought I'd close it out.....

I got the Merc 115 4 stroke in the end. It was released just as I was looking and came in at 163kg. It has now been on for about a year, although only about 25 hrs due to crap weather with no problems. The boat sits level and is incredibly quick on the plane, topping out at about 35-36kts at about 5600rpm on a 17" ali prop. It does around .9-1.4 nm per liter.

Phil M

uncle al · 20 January 2016, 12:52

another satisfied customer, happy/ safe boating. Did you try a stainless prop?

office888 · 20 January 2016, 13:43

Quote:

Originally Posted by Phil M

The boat sits level and is incredibly quick on the plane, topping out at about 35-36kts at about 5600rpm on a 17" ali prop. It does around .9-1.4 nm per liter.

What kind of load for 35kt@5600rpm w/ 17" alu prop? 4 divers + 1 operator?

Phil M · 20 January 2016, 16:16

It was lightly loaded, 2 or 2 1/2 people and no kit. The weather has been rubish for the last year so i haven't dived much. We need 2 weeks of fine weather for the adult to settle and it just hasn't happened.

I haven't tried a stainless prop yet. Really i need to see the performance loaded before i decode which way to go. I'm happy with the top speed as it is rarely calm enough to go that fast anyway on the 530 hull.

Phil M

office888 · 20 January 2016, 19:56

Quote:

Originally Posted by Phil M

It was lightly loaded, 2 or 2 1/2 people and no kit. The weather has been rubish for the last year so i haven't dived much. We need 2 weeks of fine weather for the adult to settle and it just hasn't happened.

I haven't tried a stainless prop yet. Really i need to see the performance loaded before i decode which way to go. I'm happy with the top speed as it is rarely calm enough to go that fast anyway on the 530 hull.

Phil M

Thanks Phil! I've been debating on a 90hp or 115hp for my Avon dive boat, which is a little longer and the tube diameter is a little larger than the Pro 530. Performance should be close though.

Phil M · 20 January 2016, 20:06

With the mercs, they are the same weight so no real argument not to go 115. Apart from cost i guess. Beautiful engine though. The smartcraft gauges are really good and it is almost silent on tick over.

Phil M

office888 · 20 January 2016, 20:37

Quote:

Originally Posted by Phil M

With the mercs, they are the same weight so no real argument not to go 115. Apart from cost i guess. Beautiful engine though. The smartcraft gauges are really good and it is almost silent on tick over.

Phil M

I was going to go with a Yamaha F115 4st.... 171kg.

Phil M · 20 January 2016, 20:58

Merc is 163kg. Its the main reason i chose it.

Phil M

Keepitwildak · 09 March 2016, 23:53

At what speed and loads were you obtaining the .9 to 1.4 nm/liter? I am still debating between a Suzuki DF90 or a Yam/Merc 115 and it's coming down to how much difference the fuel efficiency will be with respect to how much speed I will gain if I go with the 115...too many choices

Phil M · 10 March 2016, 11:22

Light loads, 2-3 medium bodies, 50ish liters of fuel, 17" prop and averaging around 20 kts I guess. That will include a reasonable amount of tick-over, waiting for lock gates to open etc. Top speed is just over 35kts but probably against wind and tide. I don't get much chance to fully open up as the sea is rarely flat enough around here. I used to get a similar, although slightly less top speed from a 75 clamshell with one on board but it ate fuel and the acceleration was poor compared to the 115. That was also 1 up, with the smaller, lighter console and smaller fuel tanks. I took 4 single tank divers out for a short trip once with the 75 and it was struggling to plane. I have no doubt that the 115 will manage with ease.

One thing worth noting is that the 530 changed at some point. Mine is the very old and very heavy hull with the vertical reverse chines and thick transom returns. It doesn't have the lip at the top of the transom. There may be a weight difference between the early and later models. I think my hull only weight is in the order of 250kg, according to the plate. It pushes 650kg without passengers or kit.

Phil M