Gutless 1150GS - Alternative Fuel Maps ?

[Richard P]

My 2003 1150GS (y piece and Laser exhaust ) had an appaling flat spot between 4000 and 5000 rpm and ran rough and gutless thereafter.

Have tried a motonic reset - no difference

Tried putting injector cleaner cleaner in the tank - better between 4000 and 5000 but still rough and gutless above

Tried Steptoe's fuel map modification ( the terminals are labelled 5 and 6 on my bike but the layout and position look to be the same ) but if anything it made things worse.

Are there any different combinations of terminals worth trying ?

Are there any other things to look at to cure the problem ? - it can cause the odd heart stopper on overtakes

It pulls like a train though between 3000 and 4000

Richard

 

[Sergeant Pluck]

Sounds like an actual problem to me, as opposed to tuning issue. Are the TB's balanced nicely? Valves sorted? TPS on spec? Is your lambda sensor still in place and working?

 

[Richard P]

TBs, TPS sorry for ignorance but what are they and how do I check ?

Valves ? dont know but it's only done 10k

The wire appears to be attached to the sensor

 

[Sergeant Pluck]

Throttle bodies - need to be balanced, Throttle Position Sensor needs to be within spec (I liked it nearer to 4.00 volts with an aftermarket exhaust), valve clearances need to be good ( don't assume a BMW dealership service will do/have done this ). Do you know what sort of air filter you have fittted? K&N? Those are the basic things which need to be sorted before you try to diagnose a problem. I reckon you need to get the basics sorted first, then a process of elimination will find your problem.

Good luck!

Pluck

 

[Deleted account 231205001]

Replace your coils. Had the same problem with an 03 twin spark. The new coils completely cured it. The coils are in the spark plug caps on the 03, so very easy to sort.

 

[Richard P]

The filter doesn't appear to have a name on it - just a round filter with a pink plastic core


Just looked on Sherlock website - is that the £55 each coils ?

 

[Deleted account 231205001]

The filter doesn't appear to have a name on it - just a round filter with a pink plastic core


Just looked on Sherlock website - is that the £55 each coils ?

£55 sounds about right. Like I said, my bike had identical symptons and it turned out to be one of the coil/plug caps that had corroded. Very common problem with twin spark oilheads.

 

[Carl]

better between 4000 and 5000 but still rough and gutless above

both 1150's I've owned have been rough above 5k, current one has a lovely sweet spot around 4.5 - 5k previous one was around 4k.

Look through the posts and you will see lots of complaints about running rough above 5k revs.

 

[(RIP) Kaister]

if the plug link makes it worse then i'd say it was too rich right through - which is why it pulls ok lower down

the torque curve for these engines dip around this point - if i remember right.

sounds like ignition not firing correctly - coils

or fueling need sorting - TPS and balance

 

[(RIP) Bin Ridin]

Could you refit the old pipes and zorst, to check basic conditions?

 

[davegs]

Flatulance

The air filter is the standard BMW item make sure it's not full of crap, if it looks dirty give a knock and get some of it out or buy a new filter. Best way is put the standard exhaust back and see what happens, probably go better anyway although it will be quieter lack of same seems to be the only benifit
of aftrermarkwet exhausts imho.
Dave (quiet) ghs.

 

[davegs]

Flatulance

The air filter is the standard BMW item, if it's full of crap give it a bang on the bench and get some of it out or replace same. Put the otriginal exhaust back on and see what happens. It will be quieter but look at the instruments and it will possibly go better albeit quieter. Imho the noise is the biggest
change aftermarket exhausts make!.
Dave (quiet bike) GS.

 

[ianboydsnr]

Pull each of the coilcaps a bit one at a time, you should hear a loud clacking as the spark jumps between the coilcap and plug and the engine should run rougher, if it makes no difference then the coilcap is duff

 

[Steptoe]

As others have said, sounds like a main coilcap.

Pull both the lower secondary plug caps off and see if it runs/idles on the main plugs.

If it doesn't, reattach one lower at a time to find out which main cap has failed.