slice Posted July 25, 2013 Posted July 25, 2013 Ok I have just got back from a trip down to Portsmouth, about 230 miles, and it normally takes about 3/4 of a tank there and back it's mostly motorway and dual carriageway so average speed is around 75/85, the bike is 30+ years old so not thrashing it, anyway yesterday it used 1 1/2 tanks of fuel which is way over the normal amount I have checked for leaks and split hoses (nothing) even looked in the engine oil to see if it might have drained down into the engine sump but no extra fluid in there or smell of petrol, so my question is were did it all go? I have cleaned the carbs in the winter and balanced them checked all the jets were ok & flushed the tank filter, ignition is electronic so if it runs it's working. I'm a bit stumped, does ethanol in the fuel make for LESS mileage? Any thoughts you might have would be appreciated.
Ttaskmaster Posted July 25, 2013 Posted July 25, 2013 230 miles on ¾ of a tank.... Blimey, how big is your tank??!! Fuel often makes a difference. Find a station whose fuel your bike likes. The Drag would actualy fucking bitch and moan if I dared use anything from a supermarket station. BP or Shell only, in the ideal world... fussy thing! Other thoughts to start with: Oil dirty or too thick? Air filter need cleaning/changing? Carbs need cleaning again (lots of road crap earlier on this year)? Worn tyres or incorrect pressure?
slice Posted July 25, 2013 Author Posted July 25, 2013 Thanks Tasky, I was thinking air filter myself but just fitted a new one so thought it should be ok but will whip it out and have a look at it, the tank takes about 4 gallons and I get about 65/75 to the gallon so thinking was about average of 70 to the gallon so around 280 odd miles to a tank full. But your idea of oil rings my bell not changed it for the last 5K so that's were I'm off to now + new filter, there goes my weekend!!.
Ttaskmaster Posted July 25, 2013 Posted July 25, 2013 A whole weekend for an oil change? Naw, do it in one evening, mate - Set it up to drain, go watch a movie and have dinner, come back out, do the swaps, top up and away ye go. Easy as... surely?
Noise Posted July 25, 2013 Posted July 25, 2013 What pertol did you use? Tesco ASDA?? i find that if you use the cheap shit then it doesn't last long at all. Think about it, they give you cheap fuel and you run out faster than normal so you keep going back there. Yet you buy the dearer stuff and it lasts longer than the other tat. Get what you pay for really.
nayruf Posted July 25, 2013 Posted July 25, 2013 Hi Servicing the bike will no doubt improve fuel consumption and may fully explain your bikes extra fuel usage, but during this hot weather I have just done a 200+ mile ride, it’s a regular journey for me. I noticed that I had used slightly more fuel than I normally would, the bike is as far as I can tell running fine and has had a recent service, I just figured the extra fuel usage is probably down to fuel evaporation in the tank because of the hot weather and the fact that the engine has to work a little harder to get the same engine performance during hot weather,
Moderator drewpy Posted July 25, 2013 Moderator Posted July 25, 2013 the air is not as dense in hot weather so you need to open the throttle more to get the fuel in. Also fuel expands when warm so always fill up early morning/ late at night.
slice Posted July 25, 2013 Author Posted July 25, 2013 Ok thanks all, some good points there, had not thought about it being roasting hot and that affecting the engine, makes sense when you think about it, your right will not take me all weekend to do the service and was just having a moan!!! But with air filter oil filter oil plugs (might as well) and no doubt some unexpected things cropping up I bet it's still all Saturday morning (see moaning again!!!) Plus I filled up on the motorway services so was BP not your cheapo stuff but that said I suspect that the hot journey never crossed my mind that the temp was a factor in fuel consumption.
rabmavin Posted July 25, 2013 Posted July 25, 2013 Ok thanks all, some good points there, had not thought about it being roasting hot and that affecting the engine, makes sense when you think about it, your right will not take me all weekend to do the service and was just having a moan!!! But with air filter oil filter oil plugs (might as well) and no doubt some unexpected things cropping up I bet it's still all Saturday morning (see moaning again!!!) Plus I filled up on the motorway services so was BP not your cheapo stuff but that said I suspect that the hot journey never crossed my mind that the temp was a factor in fuel consumption. hi mate . you might check for a sticky brake as my rear brake was binding slightly and caused me to use a bit more fuel . the brake wasnt even that bad .
Prichard XT Posted July 25, 2013 Posted July 25, 2013 I always use murco super un leaded the XT doesn't like shell fuel at all ?
Tommy xs Posted July 25, 2013 Posted July 25, 2013 or maybe you just got a dodgy pump in the hot weather ? could happen
dt502001 Posted July 25, 2013 Posted July 25, 2013 How old are the spark plugs ? and what colour are they could be that your spark is weak and not giving a complete burn of the fuel. Not that you ever get 100% burn but it can drop quite abit with old dirty plugs,even more with low compression. And dirty oil can efect the compression. Dirty oil and dirty plugs = poor fuel mileage
blackhat250 Posted July 25, 2013 Posted July 25, 2013 The different fuel thing , well the tankers all que up at the same refinery[ Grangemouth up here] bound to be the same stuff,,,
Campaman Posted July 26, 2013 Posted July 26, 2013 Yup, I have stopped arguing the different fuel thing as no one believes me, had it on the Subaru forums when I had a Legacy, its all produced to the same British Standard so is the same, the only difference is the additive packs. The basic kaboom from it will be the same.
mike1949 Posted July 26, 2013 Posted July 26, 2013 I just figured the extra fuel usage is probably down to fuel evaporation in the tank because of the hot weather. I concur with nayruf. When you think about it the fuel tank is exposed to extreme temperatures in this heatwave as apposed to car fuel tanks which is shaded by the car body. I've noticed before when I filled a vehicle up in this heat and left it exposed to direct sunlight the petrol started to seep out of the fillet cap.
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