xj6man Posted October 6, 2010 Posted October 6, 2010 Hello guys and gals, I know this sounds like a slightly boring question - but what would you expect a xj6's mpg in town to be? I mainly drive in London and commute to the center of town, so obviously a lot of stop start and slow driving... Over the last month or so it's slowly been declining to about 30 mpg or so now - And it's not as if I'm revving at the lights or anything, honest! Anyone else out there I can compare mpg's with? On the couple of occasions I've traveled on the motorway it's picked up a couple more miles to the gallon (a bit over 40),but nothing close to reported 50 mpg it should be able to do (I've even seen reports higher than that). Just wondering what could be affecting this (apart from my poor riding technique...) and how I can make it better. Thanks in advance!
pilninggas Posted October 6, 2010 Posted October 6, 2010 mmm, seems lower than the XJ6 that i had. Are the throttle bodies syncronised? This can really affect town mpg. Let the engine warm-up and listen to see if it hunts (the engine idle rpms fluctuate), if it is really bad you might see the rev counter dance about a bit. The yamaha idle speed is also a touch high, you may be able to tweak it down a little. On the M-way i could get 50-55mpg unless i thrashed it. If i went dead-steady 70mpg was possible. Maybe something like a tps-sensor is playing-up. on a different note - Nice to see lots of owners of this excellent bike, i really miss mine.
xj6man Posted October 6, 2010 Author Posted October 6, 2010 mmm, seems lower than the XJ6 that i had. Are the throttle bodies syncronised? This can really affect town mpg. Let the engine warm-up and listen to see if it hunts (the engine idle rpms fluctuate), if it is really bad you might see the rev counter dance about a bit. The yamaha idle speed is also a touch high, you may be able to tweak it down a little. On the M-way i could get 50-55mpg unless i thrashed it. If i went dead-steady 70mpg was possible. Maybe something like a tps-sensor is playing-up. on a different note - Nice to see lots of owners of this excellent bike, i really miss mine. Thanks for the reply mate! Thats very interesting as when I got off the bike tonight (after a half hour ride), I listened to it and it was doing exactly that - fluctuating with the rev counter shifting between 1 and 1.25 (or thereabouts). Perhaps not a massive 'dance' but there was indeed some form of huntage going on. How tricky is it to sync the throttle bodies, or is it (shock horror) a dealership issue? I'm still in warranty. The xj6 is indeed a lot of fun. excellent town bike. Tends to get a bit revvy and tetchy at low speeds - a bit jumpy even - but still very nimble and ideal for london. I've also got a Leo Vince can on it that sounds miles better than the one that came with the bike.
pilninggas Posted October 6, 2010 Posted October 6, 2010 Thanks for the reply mate! Thats very interesting as when I got off the bike tonight (after a half hour ride), I listened to it and it was doing exactly that - fluctuating with the rev counter shifting between 1 and 1.25 (or thereabouts). Perhaps not a massive 'dance' but there was indeed some form of huntage going on. How tricky is it to sync the throttle bodies, or is it (shock horror) a dealership issue? I'm still in warranty. The xj6 is indeed a lot of fun. excellent town bike. Tends to get a bit revvy and tetchy at low speeds - a bit jumpy even - but still very nimble and ideal for london. I've also got a Leo Vince can on it that sounds miles better than the one that came with the bike. to sync the carbs you need some balance gauges and a screw-driver. Google around for a guide, it is not hard. I do it myself, but have access to gauges. Give a few local dealers a call, the bike has vacuum tap points under the tank and a dealer might do it for 1/2 hours labour. The dealer you bought it from may do it gratis, but i wouldn't expect them too, as it is not classed as a warranty thing.
slowjoe Posted December 27, 2010 Posted December 27, 2010 to sync the carbs you need some balance gauges and a screw-driver. Google around for a guide, it is not hard. I do it myself, but have access to gauges. Give a few local dealers a call, the bike has vacuum tap points under the tank and a dealer might do it for 1/2 hours labour. The dealer you bought it from may do it gratis, but i wouldn't expect them too, as it is not classed as a warranty thing. I too have an XJ6 and my city mpg is about 30 mpg and motorway is about 50mpg. It is a lot lower than I would have expected, but I don't think there is anything you can do about it especially for short commute trips. The mpg is my only gripe about the bike. Good value and plenty of power for the average rider. Some cheap options, like the basic tail light but you are still getting a lot of bike for your money. With the 17 liter tank and 50mpg, you really have to keep an eye out for a petrol station at about 200 miles or you could be in trouble!
shahrie Posted December 31, 2010 Posted December 31, 2010 Hi there - I've had my XJ6S for about 3 months. Mainly I do the traditional 'extra-urban' cycle (mix of town and country roads) and have found I'm comfortably getting 55mpg - bike has just got up to 4000 miles for reference. With the torque range of the bike to be honest I'm shifting up at very low revs which obviously helps with the mpg (though conscious to not labour the engine) and find that I don't need to kick-down to overtake! Sounds like the mpg you're getting despite city riding is slightly lower and probably is down to something like the TPS needing adjustment.
xj6man Posted January 24, 2011 Author Posted January 24, 2011 Hello chaps, 30 in town and 50/55 highway sounds about right. So after riding for about 6 months I guess I can conclude that several things contribute to the low mpg I get in town - about 35/38. I think it's really down to the route I have to take every morning more than anything - Down the Euston Rd and around King's Cross, traffic jams galore, loads of stop starting. As it is I feel the xj6's is a little unsmooth at lower rpm (esp 2nd around the 4000 mark) which I assume is a R6 engine heritage, and if you add to that the fact that I bought this bike 2nd hand with a race can fitted (Leo Vince) - that's going to make tick over and low speed riding all that more fuel hungry. Wouldn't take the can off as it makes a lovely little racket and roar (plus little pops of unburnt fuel when you lay off the throttle) but it sure ain't going to help fuel economy!... I guess I could check if the carbs are synced etc, but I think the contributing factors are London riding (mostly under 30mph) and the racing can...
pilninggas Posted January 24, 2011 Posted January 24, 2011 Hello chaps, 30 in town and 50/55 highway sounds about right. So after riding for about 6 months I guess I can conclude that several things contribute to the low mpg I get in town - about 35/38. I think it's really down to the route I have to take every morning more than anything - Down the Euston Rd and around King's Cross, traffic jams galore, loads of stop starting. As it is I feel the xj6's is a little unsmooth at lower rpm (esp 2nd around the 4000 mark) which I assume is a R6 engine heritage, and if you add to that the fact that I bought this bike 2nd hand with a race can fitted (Leo Vince) - that's going to make tick over and low speed riding all that more fuel hungry. Wouldn't take the can off as it makes a lovely little racket and roar (plus little pops of unburnt fuel when you lay off the throttle) but it sure ain't going to help fuel economy!... I guess I could check if the carbs are synced etc, but I think the contributing factors are London riding (mostly under 30mph) and the racing can... Well mine was as smooth as Arthur Guiness' Finest, so it must be your race-can.
stormbringer Posted February 7, 2011 Posted February 7, 2011 Mine is 3000 miles old 60 plate XJ6S ,comute from St Albans to East London so a real mix ,never drops below 55 mpg . I have also just bought a biger front sproket so once fitted should give even more MPG. John
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