Dirty injectors or poorly fitted? Or both?

horudis82

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Good day to you all!

My GS is close to 50K miles and I've had several strange issue with it, such as:

- Feeling that the fuel/air mix is amiss, like when you have 4 cylinders and one doesn't run but here it's a 2 cylinder obviously.
- Rough idle and when using 95 petrol pingin until 3K rpm, disappears from 2.5K rpm onwards with 98 petrol.
- Vibrations that come and go depending on rpm, not really knowing what could cause it.

So, I was about to start the throttle body sync (did the valves spot on, oil and filters before a few days ago, plus four new spark plugs, went for a ride to get the engine warm and fuzzy) when I noticed that the right-hand side injector was missing its metal bracket to hold it into position, as per the picture:

Screen_Shot_2018-08-11_at_16.22.20.png



Here comes the left hand-side for comparison:

Screen_Shot_2018-08-11_at_16.22.11.png



Could this be the cause of the bike's erratic behaviour?
With a variable fuel pressure in the fuel lines depending on throttle opening, I wonder if it could move the injector in its craddle and affect the alignement of the injector's shooting angle. As there seem to be two toric joints to ensure no fuel leaks, those still allow for the injector to have some freeplay.


I took both of them out, and switched sides when I replaced them. I went for a ride, I think the bike ran better, but it could have been my imagination too.

How to spot dirty or failing injectors?
Is this missing braket that important?

Thank you!
 
I agree with Pukmeister, the allen bolt would hold the injector in position and the o-ring keeps it sealed.
I had my 40K injectors 'refurbished' for peace of mind by a firm called Brands Hatch Performance. Cost £28 and took a week or so for return by post. They give them a clean and test the injector performance.
Cant say I noticed an improvement but I can now eliminate them from my what could be wrong queries.
I also use the Tesco 99 RON fuel and that helps the running alot with improved mileage it almost pays for the difference to cheaper fuel.
 
Good day to you all!

My GS is close to 50K miles and I've had several strange issue with it, such as:

- Feeling that the fuel/air mix is amiss, like when you have 4 cylinders and one doesn't run but here it's a 2 cylinder obviously.
- Rough idle and when using 95 petrol pingin until 3K rpm, disappears from 2.5K rpm onwards with 98 petrol.
- Vibrations that come and go depending on rpm, not really knowing what could cause it.

So, I was about to start the throttle body sync (did the valves spot on, oil and filters before a few days ago, plus four new spark plugs, went for a ride to get the engine warm and fuzzy) when I noticed that the right-hand side injector was missing its metal bracket to hold it into position, as per the picture:

Screen_Shot_2018-08-11_at_16.22.20.png



Here comes the left hand-side for comparison:

Screen_Shot_2018-08-11_at_16.22.11.png



Could this be the cause of the bike's erratic behaviour?
With a variable fuel pressure in the fuel lines depending on throttle opening, I wonder if it could move the injector in its craddle and affect the alignement of the injector's shooting angle. As there seem to be two toric joints to ensure no fuel leaks, those still allow for the injector to have some freeplay.


I took both of them out, and switched sides when I replaced them. I went for a ride, I think the bike ran better, but it could have been my imagination too.

How to spot dirty or failing injectors?
Is this missing braket that important?

Thank you!

Fuel pressure is set by the fixed fuel pressure regulator and does not alter with throttle openings.

Unless the fuel pump is on its way out and the pressure will drop at full throttle. (As this is in open loop the bike will then run very lean as there is no feedback in open loop) but that`s another story.
 
Thanks for the info guys, I will adjust it with a zip tie and do the TBS.

Yup, I have stopped using 95 years ago but here it's pretty hard to come by proper 98; in my town only one station has it and not always.

Interesting about the fuel pressure, so it's constant! I will try to get new joints, I don't think they have ever been changed in over 10 years.

:beerjug:
 
Mine runs fine but has a lumpy tickover that I’ve not managed to solve. Left header runs cooler on tickover.
Swapped idle stepper motors for known good ones - no difference.
Throttle balance - no difference.
Re arranged coils -no difference.
New TOS - no difference.

The other day noticed a post saying the throttles should be balanced with adjustment on the right while the left set to zero. Not tried that yet.
 
Mine runs fine but has a lumpy tickover that I’ve not managed to solve. Left header runs cooler on tickover.
Swapped idle stepper motors for known good ones - no difference.
Throttle balance - no difference.
Re arranged coils -no difference.
New TOS - no difference.

The other day noticed a post saying the throttles should be balanced with adjustment on the right while the left set to zero. Not tried that yet.

Are you still using the PC V if so have you tried increasing the fuel a little on the 0% throttle column at 1000, 1250 RPM, first on the right hand side and see if the R/H header runs cooler.
 


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