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Old 27 April 2014, 15:38   #1
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Changing from two stoke to four stroke question

Hello

I am considering changing my current 2000 Mercury 75hp two stroke, (on my 5.4 metre ribtec) for a four stroke, purely because of the limiting factor of the amount of fuel it guzzles and the distance i wish to now go on it. It currently gets about 1.2miles per litre, however I am told i can expect to get double that on a more modern four stroke.

I have seen a 2004 Honda BF75 for sale for 1900 and it seems like it will be a straight swap with any luck. I was under the impression all the newish four strokes were fuel injected, but i am reading that this Honda may have carbs??

Can anyone shed any more light on this?

if it all checks out I am going to change to 4 stroke

Craig
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Old 27 April 2014, 16:51   #2
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Originally Posted by mctaggart View Post
. It currently gets about 1.2miles per litre, however I am told i can expect to get double that on a more modern four stroke.



Craig
They lied.

1.2m/ltr is good going and a 75hp 4st would struggle to do much better. Hang on to your money and put it towards upgrading the whole rig when the time comes. Re-powering rarely stacks-up financially.
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Old 27 April 2014, 16:57   #3
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They lied.



1.2m/ltr is good going and a 75hp 4st would struggle to do much better. Hang on to your money and put it towards upgrading the whole rig when the time comes. Re-powering rarely stacks-up financially.

For once I have to agree with Mollers completely.





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Old 27 April 2014, 17:02   #4
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Quote:
Originally Posted by mctaggart View Post
Hello

I am considering changing my current 2000 Mercury 75hp two stroke, (on my 5.4 metre ribtec) for a four stroke, purely because of the limiting factor of the amount of fuel it guzzles and the distance i wish to now go on it. It currently gets about 1.2miles per litre, however I am told i can expect to get double that on a more modern four stroke.

I have seen a 2004 Honda BF75 for sale for 1900 and it seems like it will be a straight swap with any luck. I was under the impression all the newish four strokes were fuel injected, but i am reading that this Honda may have carbs??

Can anyone shed any more light on this?

if it all checks out I am going to change to 4 stroke

Craig
It'll be carbed & you'll be disappointed
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Old 27 April 2014, 17:12   #5
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My Honda 90 s roughly do 100 Nm to 130 L as a pair 4 persons up and they are carbs
As the others say save your brass
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Old 27 April 2014, 17:26   #6
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well now thats got me totally confused, all the spec sheets etc on fuel consumption per hour and other peoples examples i have read on other forums point to 4 strokes being much more efficient?

Does anyone on here run a similar sized 4 stroke single.

What sort of fuel economy do you get? if i am doing a run across the bristol channel i get a maximum of 1.2 miles litre, or if i am just normal ribbing its more like 1.0 litre an hour.
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Old 27 April 2014, 17:35   #7
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Originally Posted by mctaggart View Post
well now thats got me totally confused, all the spec sheets etc on fuel consumption per hour and other peoples examples i have read on other forums point to 4 strokes being much more efficient?

Does anyone on here run a similar sized 4 stroke on a rib?

What sort of fuel economy do you get?
4 strokes had a period where they were better on fuel than the old tech carbed 2 strokes, but that was mostly in the time when 4 stroke went injected & 2 strokes were still "old tech". Then 2 strokes caught up with the introduction of DI, Ficht/Etec/HPDI etc. Now there's not much between 'em, but folks still fall for the "2 strokes are illegal" or "2 strokes use twice as much fuel" bollix. The 2 engines that you are comparing aren't a million miles apart, the early Hondas had problems with corrosion & I personally wouldn't chuck 1900 quid at a 10 year old one. How much fuel are you going to burn to make up 1900 quidsworth of difference? On top of that, the performance of the 75 Honda will be "pedestrian" at best. In the end it's your money, but you did ask
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Old 27 April 2014, 17:38   #8
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well now thats got me totally confused, all the spec sheets etc on fuel consumption per hour and other peoples examples i have read on other forums point to 4 strokes being much more efficient?
They are, but not double or anywhere near.

What you're proposing is a financial non-starter. You'd nowhere near see your money back in fuel saving or added resale value.

I know that you Welsh boys are tighter than submarine doors, but do the math man.
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Old 27 April 2014, 17:57   #9
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Looks like I am going to keep my money where it is then and just keep filling the greedy basdard instead

Ok new plan then, time to buy another fuel tank!
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Old 28 April 2014, 04:51   #10
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