Difficulty in Starting

[boxerscott]

Actually thats a total lie, it wont start -full stop Never had any noticeable poor performance from the engine at all. After a return from lincolnshire last autumn the bike was garaged and left for 3 weeks. When i went to start it up.. no firing at all in either cylinder. left it alone till just recently when I embarked on a clutch project. As the fuel tank was off i treated it to a new fuel filter as i reckoned this probably did not get done at 24k. Came to address the starting problem and found that I had weak sparking, the plugs were clean as a whistle and traces of fuel were present. I whipped the injectors out and tested the fuel system (as much as one can do with this method) nice even fan like spurts on cranking into a jam jar. I am thinking not enough heat to combust the petrol vapour? I can not test the Hall sensor unit or the motronic unit but can eliminate the Main coil by replacing it. Which is what I plan to do. The bike is a rather excellent example of the 1100gs circa 1995. Has anyone else had these symptons and what was the remedy?

 

[Steptoe]

Just to clear things - the bike hasn't run since you've had it apart to replace the clutch, but it was able to start and run before replacing the clutch.

 

[Comfy Old Boots]

No. He seems to be saying that the wouldn't start, he left it alone, didn't start it and then replaced the clutch without having started it.

 

[sockpuppet]

Is it fuel at the injectors or is it water maybe?

 

[boxerscott]

It would not fire before i replaced the clutch. The clutch item confuses the issue i accept, but the combustion is a seperate issue.. unfortunately

 

[BrianGriffin]

Out of curiosity, when were the spark plugs replaced?

 

[BrianGriffin]

Also, check battery connections and that it's putting out good power and not dying too quickly when it's turning the engine over.
Check out the connections on the starter motor. These can sometimes effect the amount of power going to the ignition circuit.
Your problem sounds electrical, seeing as the plugs were damp with fuel and the injectors are pumping fuel out.

 

[boxerscott]

Ive replaced the plugs, but nothing wrong with old ones. Ive ordered a replacement main coil and if that does not work ill pop the motronic unit to bmw to be tested. Battery is good as it is left on optimate and ive measured the voltage on it.

Thanks Chris.

 

[DrFarkoff]

When you crank it are you getting sparks and squirts? Is the TAcho playing up and jumping all over the place when you;re cranking it?

If so then sounds like you have the dreaded Dead Hall effect sensors

Do a Search on Hall effect sensors or H.E.S. and see the threads

P.S. if you suspect Hall sensors do NOT lift a grounded plug without at least killing the ignition or kill switch

They sort of spontaneously start sparking on thier own sometimes for a few seconds

With me it was about 10 or 15 seconds! Lesson learnt! Ow Fecking Ouch! Especially since I'd been charging the battery and it was still on the charger at 14 odd volts so there was plenty of volts for the coil to draw on!

 

[boxerscott]

My tacho is cable operated. I am getting sparks and squirts but imo weak sparks. I have had a replacement ignition coil from Motorworks but they sent me the wrong one. I have measured the resistances across both coils and primary coil is bang on at o.5 ohm secondary coil is slightly out at 12.72 Kohm should be 13Kohm. So I reckon on taking both motronic unit and coil up to BMW for them to test on there equipment. If they check out ok I will replace the hall sensor. Thanks for the helpful suggestions.

 

[Steptoe]

My tacho is cable operated. .

What model of bike did you say you have ??

 

[MattW]

What model of bike did you say you have ??

Was wondering that myself - my 1100's definitely got one of them new fangled electronic tacho's

 

[boxerscott]

DOM April 95 1100gs. Motronic unit has to be on bike to be tested. Pretty sure my coil is ok. Ignition trigger (Hall sensor) is likely to be problem i am told by dealer as motronic units rarely go wrong. Hall sensor purchase looming.