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Old 01 July 2014, 13:48   #11
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Originally Posted by Peter_C View Post
4 Stroke all the way! Environmental reasons should be the number 1 reason for them. I feel guilty every time I start my 2 stroke up and see a sheen of oil on the water.
In the small portable market where they tend to be laid on there side by mistake every so often I'm not sure a 4 stroke is actually better for the environment - have you seen the smoke etc when oil goes places it shouldn't!

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Originally Posted by Landlockedpirate View Post
But if thats your logic, surely your boat should have a stick, scraps of string and flappy bits instead ?
I don't think it follows that being concerned about needless pollution = avoiding internal combustion engines all together.
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Old 01 July 2014, 14:01   #12
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I've just gone the other way.....

I had a 2003 Suzuki DF50 on a 4.5m Avon Adventure, I now have a 2003 Tohatsu M50D2 on a SR4

Both in approx same condition and hours.

Suzuki was quiet, smooth and very economical. It loved doing 2k revs and pootle up rivers at 6knts comfortably. The hole shot was more of a relaxed affair, and at WoT I'd hit about 28kts

The Tohatsu delivers it's power completely differently, it's instant but very on or off...! It hates doing anything under 3k, and is slightly less economical than the Suzuki......but it puts a grin on my face that the Suzuki didn't..!!! It also hit 34knts with two up on Sun, without really pushing the hull.

Nothing we all didn't know really.?

However....I did have go on Tigga, and was quite surprised with the holeshot.

Would I swop..........hummmm...........nah. but on a bigger boat I'd prob want to go 4st.
The suzi 50 only pushed out 42 at the prop but the twatsoo does 50hp so you will feel the difference. put a 2014 suzi on it and it will now give it a run for its money i would guess.
Around the IOW at the weekend, (67miles) in my SR4.7 with yam 60 it burnt 72 litres mostly flat out.with a 13x19 pitch proP.
the Ribcraft 4.8 with A 60 efi i used Only 33 litres with a 13 pitch which was under propped. Have ordered a 14 pitch 4 bladed alloy for next run out.. Very substantial fuel saving.
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Old 01 July 2014, 14:20   #13
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Quote:
Originally Posted by Peter_C View Post
I feel guilty every time I start my 2 stroke up and see a sheen of oil on the water.

.
great smell though. I think any powerboater that says they care about the environment so they use a fuel efficient engine is deluding someone, probably themselves, but not me. I guess my definition of a powerboater is someone who burns fuel for fun on the water, or in the case of the Whisperers for Charity and fun. I'm honest enough to say I get my fun from burning fuel, and accordingly I can't genuinely care about the environment because I'm doing my bit to destroy it. If I did care then I wouldn't go powerboating and that ain't gonna happen.

I love 2 strokes and I could cut my tounge out for what I am about to say but yep I think 4 strokes are getting there. We have a Yammie F70 which is only 10% heavier than our 2 stroke Yammie 70 and easily has the same power and torque. In addition to that it uses about a third of the fuel, which makes me very happy as it cost me me so much less to run the boat Oh yeah and it's good for the environment!

There is a fella on the Macmillan cruise thread claiming he got round the IOW (60 Miles)in a 5.5 metre boat and only used 30 litres and I certainly believe him. that's .5 of litre per mile

So Unlike our 'enry I think weight is crucial, and when the weight is comparable to a similar powered 2 stroke then Electronic ignition and higher rrevving is going to contribute a lot toward producing from a 4 stroke the extra torque and holeshot that you experience from a 2 stroke's extra banging

Having said all those lovely things it would take a very special engine to get my Yammie 90 2 stroke of the back of my Avon 5.4 Ah the smell, the noise and the grunt and that's just me!
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Old 01 July 2014, 14:20   #14
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Why is hole shot so important? It's always the first thing 2 strokes are said to be superior in. when I go in my boat it's usually to go somewhere. the hole shot is 8 seconds of a day trip. Why do I care if it's 8 seconds or 12?

I'm running a 250hp 4-stroke so maybe this is a portable engine conversation?

jason
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Old 01 July 2014, 14:28   #15
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Quote:
Originally Posted by Bigtalljv View Post
Why is hole shot so important? It's always the first thing 2 strokes are said to be superior in. when I go in my boat it's usually to go somewhere. the hole shot is 8 seconds of a day trip. Why do I care if it's 8 seconds or 12?

I'm running a 250hp 4-stroke so maybe this is a portable engine conversation?

jason
Are you the type of boater who gets on board, sets the throttle (usually to full) and then sits back for several hours? Either you only go in flat calm conditions or would find working the throttle more comfortable - in which case acceleration is nice to have.
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Old 01 July 2014, 14:33   #16
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Originally Posted by Poly View Post
Are you the type of boater who gets on board, sets the throttle (usually to full) and then sits back for several hours? Either you only go in flat calm conditions or would find working the throttle more comfortable - in which case acceleration is nice to have.
JV's on the west coast of California; I can pretty much guarantee he's not going to get a lot flat calm days.

But your response doesn't really address his statement (or question or whatever it was): Hole shot performance is nice to have, but it only applies to the times you are starting off after dropping off plane. As he said, that is generally a very small percentage of the time on the water.

jky
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Old 01 July 2014, 14:47   #17
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Originally Posted by Rogue Wave View Post


great smell though. I think any powerboater that says they care about the environment so they use a fuel efficient engine is deluding someone, probably themselves, but not me. I guess my definition of a powerboater is someone who burns fuel for fun on the water, or in the case of the Whisperers for Charity and fun. I'm honest enough to say I get my fun from burning fuel, and accordingly I can't genuinely care about the environment because I'm doing my bit to destroy it. If I did care then I wouldn't go powerboating and that ain't gonna happen.

I love 2 strokes and I could cut my tounge out for what I am about to say but yep I think 4 strokes are getting there. We have a Yammie F70 which is only 10% heavier than our 2 stroke Yammie 70 and easily has the same power and torque. In addition to that it uses about a third of the fuel, which makes me very happy as it cost me me so much less to run the boat Oh yeah and it's good for the environment!

There is a fella on the Macmillan cruise thread claiming he got round the IOW (60 Miles)in a 5.5 metre boat and only used 30 litres and I certainly believe him. that's .5 of litre per mile

So Unlike our 'enry I think weight is crucial, and when the weight is comparable to a similar powered 2 stroke then Electronic ignition and higher rrevving is going to contribute a lot toward producing from a 4 stroke the extra torque and holeshot that you experience from a 2 stroke's extra banging

Having said all those lovely things it would take a very special engine to get my Yammie 90 2 stroke of the back of my Avon 5.4 Ah the smell, the noise and the grunt and that's just me!
I know exactly what you mean about the Yam 90, dad had one on the family ski boat as a kid, awsome piece of kit.

But I think you understand what I am trying to say, 1 of the big negative factors of 4 strokes is weight, and thats starting to come down. (the Yam F70 is our shortlist of 2 to replace dads ageing Honda 50 on his sailing boat).

Personally I'm still sticking with my collection of transportable 2 strokes for now.

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Old 01 July 2014, 14:54   #18
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Originally Posted by matt h View Post
The suzi 50 only pushed out 42 at the prop but the twatsoo does 50hp so you will feel the difference. put a 2014 suzi on it and it will now give it a run for its money i would guess.
Around the IOW at the weekend, (67miles) in my SR4.7 with yam 60 it burnt 72 litres mostly flat out.with a 13x19 pitch proP.
the Ribcraft 4.8 with A 60 efi i used Only 33 litres with a 13 pitch which was under propped. Have ordered a 14 pitch 4 bladed alloy for next run out.. Very substantial fuel saving.
I burnt roughly 28-29 liters on round IoW with my 2 stroke (granted it is DI though!)
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Old 01 July 2014, 14:56   #19
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Hole Shot is not only nice to have...but positively essential in the Rough Stuff!
My 250 DF Suzuki delivers Great Hole shot,is Whisper quiet, Clean running and Cruising returns about the same fuel economy as the 130 etec!!!...and no oil to worry about Love it.
I would say that the smaller the RIB,the more important the weight consideration.
Also the importance of the right Prop for the type of Boat....and Boating you do is not to be underestimated.
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Old 01 July 2014, 15:07   #20
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Quote:
Originally Posted by Bigtalljv View Post
Why is hole shot so important? It's always the first thing 2 strokes are said to be superior in. when I go in my boat it's usually to go somewhere. the hole shot is 8 seconds of a day trip. Why do I care if it's 8 seconds or 12?

I'm running a 250hp 4-stroke so maybe this is a portable engine conversation?

jason


Blimey, running a SIB with a 15 2 smoke on and off the beach and along the coast in typical UK conditions the hole shot on and off is a heck of a lot more than 8 seconds in a day, more like 50%!!
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