Poor Fuel Economy

[TomGrainger]

For some reason, my fuel light starts blinking at just under 100 miles on my SV650, but most people are telling me they get more like 130-140. I really don't understand why this could be. I usually cruise at 4k rpm and change at about 5k. I mostly use the bike during my commute, which has a lot of waiting at red lights. Could this be the cause?

[Mr Fro]

Dirty air filter maybe?

How much fuel are you putting in, what is your tank volume and what is your theoretical reserve? Could be that your fuel level sensor is on the wonk.

[mealexme]

More than likely a faulty sensor. Next time, don't fill up until the light appears, then take note of how much petrol you put in. See if you can find a user manual, it should tell you how much fuel should be left when the light comes on and how much the tank holds. Do the maths and you can tell if its just the sensor.

PS, looks like Mr Fro posted the same idea before I hit submit

[klingelton]

first time i filled up my big bike, i put the nozzle all the way in the tank. then panicked because i only got 89 miles out of a tank. then i realised what i'd done and felt a real lemon.

not saying that you are, but are you a lemon like me?!

[TomGrainger]

Fortunately not a lemon haha, but thanks for the suggestion. I'll take a look at the fuel sensor idea and report back. The fuel light was at the blinking stage when I got to work today so I'll be able to test it. I'll leave it till the light's permanently on then I'll fill up and do some maths.

[GazW]

Do as above but for a different conclusion. Brim your tank, then when your fuel light comes on, brim it again, make note of how much you put in, so say it takes 13 litres for the fuel light to come on, then compare it with how much your tank holds. You may still have 4/5 litres when your light is on.

I can get 160ish miles from a tank, but go on reserve at 110ish. Your fuel light may kick in when you've still got another 40 miles in your tank. It's not going to come on to tell you you've ran out. It's telling you you should think about filling up. There will be a bit of room for error in it, what would happen if your light came on and you were miles from a station?

You could just reset your trip meter when you fill up, then next time you fill up you will know how far you've gone and how much you've used and work out the MPG. Then compare that to what you should be getting

[Stu]

4 litres at flashing light and 2 litres left at solid light

these sensors dont go faulty and if they do they dont work

they are a heat sensor and they work by the fuel keeping them cool when the fuel is below it the sensor heats up causing the fuel light to come on

is the chain and sprockets the right size? if you are running different size your mileage will be off

also what year is it? if its the injected model is it getting to temperature? IE above 80 degrees if not it will be running on the cold map all the time which will just dump fuel into the cylinders

[Stu]

looking at your profile I can see its a pre injection model so forget the running temp suggestion

[TomGrainger]

Ok so I fueled up today having done 111 miles when the solid fuel light came on and I put 13.86L in. That works out at 36MPG which sounds absolutely shit to me. I don't know what size the chain and sprockets are but I believe they are standard size.

[banditjohn]

Your MPG is as you say rubbish, the important bit is how you ride and then is your mileage correct If you have a sat nav and can compare the two that'll give you a better idea Moving on to the next part will be OK if you know a little bit about your bike but how is it running, do you have a flat spot, have you changed the air filter as one of the previous post's, is it still the stock can and is the end really sooty. You might find that the carb's could do with a clean and I generally throw a good dose of Redex in the tank and have found it pretty good stuff and normally does the trick.

Hope you can get the problem sorted and it'll probably end up a good reason.

All the best

John

[Guest]

Does seem a little on the low side. I get 120 miles before hitting reserve and 90% of my miles are in london traffic.

Are you smelling any petrol? how's your idle? when was the last service? Any more symptoms you can think of that's not as it should be???

[TomGrainger]

I'm wondering if perhaps I should service the bike. The seller claimed January (I bought it in March) but had no receipts for parts. The exhaust is stock and I haven't changed the air filter. Maybe it's time for a full service and a bit of redex in the tank. Sound sensible?

[Chrissb6]

Hi just a thought, is the bike easy enough to push? Just check and make sure that the brakes are free and that the none of the pads are dragging. I've just fitted new pads to the front of the Busa and notice that one of the pistons was sticking causing one of the pads to ware unevenly.

[Guest]

I still want to know if there's any other symptoms... if would help all the guessing going on...?

[Chrissb6]

I still want to know if there's any other symptoms... if would help all the guessing going on...?

There's plenty Mate all can drag fuel consumption down,

Riding technique, riding erratic , revving the engine out and not changing gear at the correct time all burn fuel unnecessary. l've know riders to drag the rear brake due to the foot covering the pedal all the time. Then there's the engine, wheels tyres and chassis to get into. I sure he will find something along those lines that will expose the problem.

[Guest]

I still want to know if there's any other symptoms... if would help all the guessing going on...?

There's plenty Mate all can drag fuel consumption down,

Riding technique, riding erratic , revving the engine out and not changing gear at the correct time all burn fuel unnecessary. l've know riders to drag the rear brake due to the foot covering the pedal all the time. Then there's the engine, wheels tyres and chassis to get into. I sure he will find something along those lines that will expose the problem.

I think my point may have been missed...

OP states the bike isn't getting as many mile as believed would be normal. What I'm asking is for any other clues that may help in diagnosing if it is indeed abnormal, a rider created problem through technique etc or a mechanical issue.

Any extra information on riding (frequently in the high RPM's, harsh accelerating/breaking etc) would be helpful as would anything mechanically abnormal such as backfiring, wet plugs, leaks etc.

As it is, the original question is a well opened can of worms surely...

[TomGrainger]

I'm actually currently at odds with my clutch. I've been having trouble clicking up into neutral from first when at a standstill. I have looked at the clutch cable and there is no room to adjust from that end, so I'm going to take the sprocket cover off and investigate at the weekend. Could this be part of the issue? My tires have recently been inflated, so it's not that. Chain is adjusted and lubed and has no tight spots. I'm pretty sure my back brake isn't dragging (I keep my foot away unless braking), so really not too sure. Perhaps a service is needed, but beyond that I don't know.

In terms of riding, I use it mostly for commuting and cruise at 4k revs, changing up around 5k (I don't have to go above third on my commute). I'm pretty steady with the bike tbh.

[acting_strange]

I'm actually currently at odds with my clutch. I've been having trouble clicking up into neutral from first when at a standstill. I have looked at the clutch cable and there is no room to adjust from that end, so I'm going to take the sprocket cover off and investigate at the weekend. Could this be part of the issue? My tires have recently been inflated, so it's not that. Chain is adjusted and lubed and has no tight spots. I'm pretty sure my back brake isn't dragging (I keep my foot away unless braking), so really not too sure. Perhaps a service is needed, but beyond that I don't know.

In terms of riding, I use it mostly for commuting and cruise at 4k revs, changing up around 5k (I don't have to go above third on my commute). I'm pretty steady with the bike tbh.

 

I personally think the problem 1st to Neutral is a common G/box issue with Suzuki's...I had the same problem with my SV and sometimes have the same with my Strom....I don't worry about it...

[Chrissb6]

In terms of riding, I use it mostly for commuting and cruise at 4k revs, changing up around 5k (I don't have to go above third on my commute). I'm pretty steady with the bike tbh Quote

Hi Mate, I think you have answered your question. There's no way your going to get decent fuel consumption figures if the bike is not getting any higher than 3 gear on your travels. The best fuel figures are achieved cruising in top at a steady speed. I would Take it out on a decent run and check it again before you start spending money on what might be unnecessary services and repairs.

A read here might help explain

http://www.dft.gov.uk/vca/fcb/faqs-fuel-consumptio.asp

[Guest]

Having looked on MCN and done some calculations...it doesn't appear to be a problem.

It does 100 miles commuting gears 1-3 then you hit reserve and need to fill up?

It's got an advertised mpg of 40 and a tank range of 135miles... that kind of sucks seeing as mine is better on fuel (no wonder I am getting more before hitting reserve).

I'd expect what you're getting tbh and in motorway - 140miles then reserve at a guess.

[Rad]

also what year is it? if its the injected model is it getting to temperature? IE above 80 degrees if not it will be running on the cold map all the time which will just dump fuel into the cylinders

Don't want to hijack the thread but my (injected) SV runs at 70 degrees. I had it go up to 90 only twice in slow traffic and a hot day. Should I look into this? That said I get 44-46mpg despite being throttle happy

[Stu]

also what year is it? if its the injected model is it getting to temperature? IE above 80 degrees if not it will be running on the cold map all the time which will just dump fuel into the cylinders

Don't want to hijack the thread but my (injected) SV runs at 70 degrees. I had it go up to 90 only twice in slow traffic and a hot day. Should I look into this? That said I get 44-46mpg despite being throttle happy

 

Yes look in to it and see what temp is normal

What I posted was an example of my bike but pretty sure the SV will run at the same temp

[DreamytimeEscorts]

I know it's a totally different bike but my zx7 does a lot less in a commute than when I thrash it.