4 strokes for a Cat

[julian1]

I have an early Noosa Cat 660 (basically old 20' Sharkcat with pods and a bit lighter) and have been thinking about upgrading the 130 yammies for some 4 stroke economy. Have been thinking about the 140 Suzy but maybe a bit underpowered, but also the 150 Yammie excellent power but will they be too heavy at 220kg ? has abyone done this too their Cat ? the current yammies weigh only 169kg's and the boat is balanced beautifully I think it could take more weight but not too much. Is there a suitable 4 stroke ?

[ziggy.]

Julian1
Mate I have been down this path to some extent only my experiences are with the 7.4 mtr model, one a sharkcat and now with a Noosacat. The first boat had twin V4 140 Evenrudes on it with engine wells not pods and I have to say they were a good match for the boat cruised at 50 ks at 4500 rpm, after five years of storage and no use I decided to replace them and to try to keep the story short I did seriously consider twin 140 suzys because the weight was similar and the power was equal or better than what I had, I would think that two of these may be a tad on the high side as far as horsepower goes for your boat, but as you know the setup that you have now would have to be close to perfect and thats probably due to the weight of the yamahas.

This story goes on forever but for what its worth I decided against the fourstrokes and my first choice was 150 hp E-TECS, the power is great the weight is also a winner and the fuel economy is as good as any fourstroke and they are still to some degree a simple two stroke. There is so much choice out there unlike years ago, I think the big thing is weight, to much on the back can ruin a good boat. As for me I didn't get my first choice mainly because the dealer lost the evenrude dealership so I turned to Yamahas, a pair of HPDI 150s these weigh the same as the 150 fourstroke that you mentioned, the boat is not on the water yet but soon I hope 3-4 weeks fingers crossed.

Evenrude offer a 115 e-tec which would suit your boat really well but also I think suzuki are good if you really want fourstrokes I am just not sure about the weight, you have got a really nice boat there so you want to make the right decision. I have noticed that Kevlacat fit nothing but suzukis , a bit of food for thought.

[crazboutfishin]

Julian1

Suzukies and Evinrudes. You've got the Suzuki with amazing technology with the 175 and 250 having variable valve timing which is a must have in todays society with the rising fuel prices, surprising power for a fourstroke and I havent heard a bad word about em. From the Suzuki site. (Other advanced features include multi-stage induction and a 32-bit onboard computer which monitors engine sensors and controls the multi-point sequential fuel injection system.) You are starting to see more and more boats with them.

Then you have the Evinrude which also are very technologically advanced. They are as quiet as a 4 stroke, as economic as a 4 stroke, they put out less emissions than Verados and Yammies 4's, they can run on no oil for 4 hours or more, they consist of a rope start system which is very safe, they feature only 2 head components as others have over 200, they have no service for 3 years (you probaably already know that) but most importantly you are still getting the brute power of a 2 stroke.

Between the two they are so good that if you bought either of them you would be happy. But my opinion would have to be the Suzy as I have heard alot more about them and they are on so many boats. Also i am seeing that alot of coast gaurd services are starting to use them. I havent seen many e-tecs on boats so im unsure. They can talk the talk but i'm not sure if they can walk the walk.

Good luck with your choices.

Crazy

[julian1]

thanks guys, but I know the Suzy 140 would be good and probably the most weight I would want but they are only 128hp, at the moment my 130 yammies would have more grunt and are lighter, and I am actually wanting a little more, I reckon 150's would be perfect when loaded heading out to the shelf. does anyone know if the yammie 150 4 stroke would be just too heavy at 220kg's ? they would have plenty of power as they are actually around 160 hp
I think if I spent the money 4 strokes would be the way to go, but it is still that power to weight issue.

[fishingrod]

Throw some extra weight on your pods next trip. Get it as far astern as you can to simulate the weight of a bigger outboard.

Then see what kind of attitude you get.

Even if the motors are marginally too heavy, a change in props can make some difference. There are a lot of mixed thoughts about foils so i wont go there.

My only experience has been on board a 7m SharkCat with twin o/bs. It was running factory props and was fine. Someone decided to put a set of Permatrims on it and it made no difference in my opinion. (but there was no problem in the first place)

Rod

[dfox]

There are new 660's fitted with 150 yammy 4's. I know of one fella who put them on just so he had more power then his mate who has 140 suzuki's (rev heads). I havent been in either boat so cant comment on how they carry the weight. I'd ring noosacat and ask them what they recon as well as water test your boat with sand bags on the pods ...foxy

[reef_king]

Mate if i was in your position and was conncerned about the extra weight I would go the suki 140's, I don't know who told u they only develop 128hp but thats crap and would be called 130s if this was true, they develop 103kw or 140 (out of suzuki manual)
the engines wheigh 189kg each and for the 20kg a side more, u can easly save those weight figures in extra fuel u'll carry with ur current yammies, i asume you also carry oil on board as well......

People are under the impression that the etecs use less fuel than a four stroke(?were do they get this from ) as this is only at wot and d.s.t...... a mate has a 115hp etec pushing a 5m pressed alloy boat and it use's 25-26lph at 4000rpm compared to my 140s that use 15lph each at same revs. True the 140s aren't as powerful as the 150hp 4/s yammie/honda etc.. but are much cheaper per engine to buy origiannaly(around $6000 for the pair was the price i was quoted 6 months ago) also if ur after longetivity/engine hours can't go wrong with a 4 stroke.

ty

[crazboutfishin]

Thanks for clearing those fuel facts up for me Ty. I was just going off the E-tec dvd.

Cheers
Crazy

[lippa]

Mate if i was in your position and was conncerned about the extra weight I would go the suki 140's, I don't know who told u they only develop 128hp but thats crap and would be called 130s if this was true, they develop 103kw or 140 (out of suzuki manual)
the engines wheigh 189kg each and for the 20kg a side more, u can easly save those weight figures in extra fuel u'll carry with ur current yammies, i asume you also carry oil on board as well......

People are under the impression that the etecs use less fuel than a four stroke(?were do they get this from ) as this is only at wot and d.s.t...... a mate has a 115hp etec pushing a 5m pressed alloy boat and it use's 25-26lph at 4000rpm compared to my 140s that use 15lph each at same revs. True the 140s aren't as powerful as the 150hp 4/s yammie/honda etc.. but are much cheaper per engine to buy origiannaly(around $6000 for the pair was the price i was quoted 6 months ago) also if ur after longetivity/engine hours can't go wrong with a 4 stroke.

ty

I am led to beleive the suzuki's do only devolop 128hp. its the 10% marketing thingy (for want of a better word) that company's can get away with! do the math, you'll soon see they are in there legal rights to call a 128hp motor a 140hp.
but as always, someone please correct me!

cheers

lippa

[Gunfish]

I am led to beleive the suzuki's do only devolop 128hp. its the 10% marketing thingy (for want of a better word) that company's can get away with! do the math, you'll soon see they are in there legal rights to call a 128hp motor a 140hp.
but as always, someone please correct me!

cool, I've never done that before!

From the Suzuki web site the DF140 creates a max output of 103.0kw. This converted to hp = 138.1253 hp, enough said. The weight for the DF 140 is 186kg for the long and 191kg for the x-long. I only wish I had your dilemma. Hope this helps and good luck.

Mabo.

[julian1]

yeah I know the website says that but the general word from mostr people in the know is that they are only 128hp. so they would be around the same power (but 4stroke curve) but more weight, this will equal worse performance. I have to remember taking off 10kg's of oil each side though but these are in front of the engines. has anyone put 150 yammies or honda's on a similar boat ?
maybe my only choice is optimax or etec ?

[joey_1987]

Here it lists the 140hp zuke as developing 138.1hp@5900rpm, http://www.boatpoint.com.au/portal/a...opDefault.aspx
Cheers.

[Sportfish_5]

yeah I know the website says that but the general word from mostr people in the know is that they are only 128hp. so they would be around the same power (but 4stroke curve) but more weight, this will equal worse performance. I have to remember taking off 10kg's of oil each side though but these are in front of the engines. has anyone put 150 yammies or honda's on a similar boat ?
maybe my only choice is optimax or etec ?

Sorry but that 128hp claim is just a load of internet BS about the Zukes. Get the people "in the know" to actually post some dyno figures to prove their claim. They are without peer in the 115 to 140 4 stroke class so this crap prolly was generated by the opposition who have had their bums smacked in market share by this model. I have owned one and they are a very strong and fuel efficient engine and I would not hesitate to own one again on a suitable boat.

[lenm]

Just a though - check out F&B latest publication dedicated soley to cats. I saw it in the newsagent the other day.
It had an article about repowering older cats with 4 strokes and in general suggested going as light weight as possible. Might be a dissapointment in the handling department if you try to bolt on too much weight.

[reef_king]

Greg p. ur right on the money It probablly the opposition,or salesman B.S

I have been on cats with 2x 130hp 2stroke yammies and the exact same hull with 2x140hp suke's and guess which one had more power?the suzukis had a higher top speed and higher cruise speed, with same weight on board and conditions, If they are only 128hp...... there good.

Just about every pro that has a cat in the 6.5-7.5 m range on the sunny coast has 2 140hp suzuki's on them with a few opting for the yammies and hondas in the 100-150 hp range, I'm yet to see an etec or optimax on one.Just a thought. I'm not saying the 140's are the absulote best as I would like a 150hp honda vtec(bit more power and economy) on my transom as my boat has no problem handling the weight, however, the origanal Q. is concerning weight and the 140's are the leader in power to weight in this range with better economy over the 2-stroke competiters