evinrude using allot of petrol

harry101

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Oct 9, 2004
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i have an evinrude 20hp which although it runs well is using a hell of a lot of fuel, even when its on a lean mix - any suggestions or is this usual for an old engine??? (about 17yrs)
 

fireman57

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Re: evinrude using allot of petrol

that engine is not that old. Did it just start using more fuel or has it always done it. If it has always done it then it probably will continue to. As long as it is perfoming well it is probably okay. I have a 1991 25hp that uses a lot also. I do a lot of idling and it just seems to drink it. When I run WOT it uses more than my brothers '78 35hp.
 

harry101

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Re: evinrude using allot of petrol

cheers- with the price of petrol here in England (nearly a pound a litre (($1.6)) means its costing me about £10 to do a 5mile round trp - might find another outboard!
 

fireman57

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Re: evinrude using allot of petrol

We are at two dollars a gallon (little more than 50 cents a liter) here. How many litres is it taking you for this 5 miles? I can run for about 2hours at WOT on 4.5 gallons.
 

harry101

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Re: evinrude using allot of petrol

12 litres (dont know how many gallons that is as there making us go bloody metric)just over £10 worth
 

fireman57

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Re: evinrude using allot of petrol

That would be a little over four gallons here. How long does it take you to go the five miles? Are you idling, wide open, or half-throttle? Are you pulling a good load? What size boat is this on? Also did it just start doing this or has it always done this?
 

fireman57

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Re: evinrude using allot of petrol

Paul is right I meant a little over 3 gallons as your litre is just a little more than our quart.
 

Paul Moir

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Re: evinrude using allot of petrol

A question to add to fireman's - what do the firing end of the spark plugs look like (colour, comparison)? Are they somewhat new?<br /><br />10% rule is pretty much true for all engines; 2-stroke, 4-stroke new and old (except the fat 50, which seems to have a 20% rule!) That is, 10% of a engine's HP is how fast it consumes gas in US gallons/hour at WOT. So a 100hp engine consumes 10 gallons per hour at full throttle. For us metric-talkin folks, that's .4l per horsepower per hour. So a 5hp engine consumes 2l per hour at full throttle.<br />Back off to about 3/4 RPMS to find your most fuel efficient running. Consumption goes way up in that last bit of throttle. At idle and midrange is where you find the wonderful economy improvements in modern outboards.<br /><br /><br />PS - 12l is 3.2 US gallons. Try searching Google for '12 liters to gallons'.
 

umblecumbuz

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Sep 25, 2004
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Re: evinrude using allot of petrol

Handy site:<br />(Convert anything to anything.)<br /> http://www.onlineconversion.com/ <br /><br />Remember please that US gallons are smaller than UK gallons. 'Bout the only thing that is!!<br /><br />One litre is about one and three quarters of a UK gallon.<br /><br />Now who's confused?
 

petrolhead

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Oct 16, 2003
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Re: evinrude using allot of petrol

"One litre is about one and three quarters of a UK gallon.<br />Now who's confused?"<br /><br />Er, I think you are! <br />Surely you meant to say 1 litre is about 1.75 PINTS not Gallons? And don't forget that those UK Pints are bigger than US ones too, a full 20 fl oz rather than the diminutive 16 that our colonial friends use.
 

steviecops

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Oct 3, 2003
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585
Re: evinrude using allot of petrol

There are 4.46 litres to a U.K gallon........I think! So a litre is just under a quarter of a gallon.
 

umblecumbuz

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Sep 25, 2004
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Re: evinrude using allot of petrol

Petrolhead and Steviecops<br /><br />Yeah - you're right and I'm wrong.<br />Got the English contingent going, though, didn't it!<br /><br />Ciao
 

fireman57

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Aug 24, 2004
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Re: evinrude using allot of petrol

one liter is 1.06 U.S. quarts. The Imperial Gallon is more than the U.S. gallon. But we still don't know how much fuel he used to go the 5 miles and at what throttle he was at. Had my 25 out yesterday and ran two hours and 35 minutes on a little less than 6 U.S. gallons.
 

fireman57

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Aug 24, 2004
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Re: evinrude using allot of petrol

Harry I still hav been thinking about this and I have to ask. Do you have this engine trimmed so it's not "plowing" the boat? You are right that this engine seems to use a lot of petrol.
 

umblecumbuz

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Re: evinrude using allot of petrol

Following Firemans ...<br /><br />What type of boat? Makes a big difference to consumption!
 
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