Odd progressive fuel economy failing.

[jtw000]

Ok. I've had my 1200gs 04 for around 6 months. I love it but I think I've just about had enough of it now. I've got a new problem that makes no sense so see if anyone here can shed some light on it. The fuel economy is lousy and gets progressively worse. I set my trip every time i put a tenner in and watch what it does. When I first got it it did just under 100 miles, around 90 if I used it enthusiastically. Then it started getting worse so i changed the plugs. I cleaned the engine with redex. I got a straight through exhaust. All these things worked but only about a tankful. I changed the plugs last week, they were sooty, old and one had a bent pin so the gap was far too small. New plugs (same ones) made it jump straight up to 111 to a tenner, next tank did 95, next tank down to 85. No matter what i do the economy gets worse and worse progressively. Valve timing out? ECU fault? O2 sensor? I think it might be time to trade this for an 1150 but the weight and thought of even less power puts me off. I use this bike for everything, including light off road work and think the 1150 might be just too big and have heard less than encouraging things about the 800. I'm planning some touring next year and bought this with that in mind. After reading all the horror stories about reliability here and my own niggles would I be better off buying a KTM?

 

[Mr K]

Air filter?

 

[MartinL]

Air filter?

Concur. Could be a sensor issue also but it escapes me why you would start modifying exhausts and bashing Redex through it before you've carried out a basic service - valve clearances / throttle synch / filters etc etc.

How are you using it? I.e mileage of typical journey etc.

 

[Mr K]

Concur. Could be a sensor issue also but it escapes me why you would start modifying exhausts and bashing Redex through it before you've carried out a basic service - valve clearances / throttle synch / filters etc etc.

How are you using it? I.e mileage of typical journey etc.

..and of course the price of petrol may have an effect..

 

[MartinL]

..and of course the price of petrol may have an effect..

Yeh, maybe he should have bought the diesel version

 

[jtw000]

It's the not the fuel price, it's been constant and still showing big differences in milage, always on a downwards spiral. Air filter was switched to a K&N when the exhaust was changed and it was misbehaving before.

 

[Magwych]

My 08 GSA does that, when it starts to get worse I do a TPS reset and all seems well again.

Thanks for reminding me . It is due a service next week ( 36K miles) so will mention it then. So long as I don't forget by then

 

[ktmmark]

Some times it pays to get a code read,will show if it is a sensor or not

 

[Magwych]

My GS-911 shows no recorded faults. My guess that it is either "adaptive" programming in the ECU, desparately trying to get the Kg CO2/100 km down to meet the latest requirements, or the TPS going off calibration over time.

My journeys are relatively predictable, and I really do notice when I get less than 328 miles to a tankful. Soon as I do a reset I can get around 360 ( but usually fill after my regulation 328 miles).

 

[jtw000]

How do i do a code read?

 

[Sgt Bilco]

So, lets get this straight...85 miles on a tenner is around 40 mpg @£1.05 per litre which is OK ish. I get an average of 44 over all types of use.

What roads are you on? Are you commuting? are you thrashing the bejazuz out of it?

I suspect the straight through pipe and K&N don't help. You should really be looking at a power commander to sort the fuelling with that set up. Are you running with a baffle in or out? The engine needs a bit of back pressure to run really nicely so try with the baffle in and a standard filter.

Oh, if you want good fuel consumption. I wouldn't call in to the KTM garage

 

[Timolgra]

TPS...

 

[Magwych]

How do i do a code read?

You will need either a GT-1 ( dealer owned computer) and software, a GS-911 device, or find someone that has one. Unfortunately that means a dealer for the first,; or, for the latter buy one or find someone that has a pro version and is willing to check for you.

The free check is to do a TPS reset.

Put key in ignition barrel, engine kill switch to run, and turn the key to "on".
Do NOT start the engine.
Open the throttle smoothly all the way to full throttle, then close to fully closed, repeat the throttle movement two more times.
Turn the ignition off, then back on again.

That's it.

It will take you about 10-15 seconds and cost you nothing. Got to be worth a try ?

 

[RickG]

It does sound like a sensor is to blame but like the others say the K&N and pipe will add to any confusion.

I've been doing the same trip every day for many years on GS's so I notice subtle changes in fuel consumption which over a period of weeks is generally very, very consistent. However, I always get about 20-30 miles less per tank in the depths of winter compared to summer. It may be simply the cold, thicker oil and the sensor's different responses but it may also be differences in the fuel from winter to summer

 

[Paul Wakefield]

How are you measuring your fuel consumption and how do you know when you have used a tenners worth (I assume you are not running it dry)?

Better to fill the tank and work out the consumption that way - will give much more consistent readings.

Still sounds as if something needs sorting though.

 

[EggChaser]

I know there are differences between the engines etc between the '04 and '08 models but do the early 1200s really only get 100 out of a tank? Or has something blocked the vents on the tank and sucked it in (like someone reported on a GSA recently)

my '08 gets between 180 and 220 out of a tank unless I really, really am going for it.

 

[karnevil]

Ok. I've had my 1200gs 04 for around 6 months. I love it but I think I've just about had enough of it now. I've got a new problem that makes no sense so see if anyone here can shed some light on it. The fuel economy is lousy and gets progressively worse. I set my trip every time i put a tenner in and watch what it does. When I first got it it did just under 100 miles, around 90 if I used it enthusiastically. Then it started getting worse so i changed the plugs. I cleaned the engine with redex. I got a straight through exhaust. All these things worked but only about a tankful. I changed the plugs last week, they were sooty, old and one had a bent pin so the gap was far too small. New plugs (same ones) made it jump straight up to 111 to a tenner, next tank did 95, next tank down to 85. No matter what i do the economy gets worse and worse progressively. Valve timing out? ECU fault? O2 sensor? I think it might be time to trade this for an 1150 but the weight and thought of even less power puts me off. I use this bike for everything, including light off road work and think the 1150 might be just too big and have heard less than encouraging things about the 800. I'm planning some touring next year and bought this with that in mind. After reading all the horror stories about reliability here and my own niggles would I be better off buying a KTM?

Where do you get your fuel?
Supermarket?Sack it its crap.
If not that then I dunno.

 

[Sgt Bilco]

I've been thinking about this today and I reckon you aren't taking true mpg figures. There are too many variables in just sticking a tenners worth of fuel in the tank because unless you run it completely dry, you are never going to get the same level twice.

You need to fill it up each, and do manual mpg calculations and not bother with the guage to get true figures.

 

[Snoopy]

100 mile for £10 quid is reasonable.

If you want more mileage, put more than a tenner in it.

 

[jtw000]

The variables are within acceptable tolerances. My brother had an adventure and we clocked the same milage within half a mile over 150 miles so I therefore accept the accuracy of my gauges over a distance. When going to reserve and flashing a warning the bike was recharged within 3 miles and still showed considerable variance. While not scientific there is a general pattern of reduced quality in terms of fuel performance. I do not expect more than 100 miles to a tenner although my last Fireblade delivered 160 miles to the same money with carbs, (they are the future) with performance far in excess of what this is capable and while run, in specialist terms, with the nuts screwed off it.