Cutting out

[bricking it]

Thanks chaps, i will have a look round tonight for the obvious stuff, if i cannot find anything i will have a look at the hall sensor thingy after that.

[oyster]

Someone here identified what the sensors were, listed the Radiospares (?) part numbers. They were about £12 each. Of course, I do not have a clue myself what they were.

[Dai wiskers]

That's the one Steve it is a replacement unit with better wiring than the BMW one
The one's Dan does use the BMW base plate new sensors and better wiring
Usually it's not the sensors that go but the wiring the sensors come with good heat resistant wiring attached but BMW in their infinite wisdom join this to normal automotive wire for the run up to the connector then to cap it off they fix this unsuitable wire to the crankcase at the hottest part in a rubberish grommit that melts this inturn melts the crap wire BMW use bringing the bike to a stop never to run again until sorted

The symptoms mine gave were the bike ran fine just the odd miss now and again but with the work on my fueling and the motor being rebuilt with unmatched barrel and piston on the left hand side i put it down to this and thought no more about it (you know the sort of thinking never mind the rattles get out there and screw it up )
Anyway after a blast up to the Lake District we decided to break the return journey by stopping overnight in Llangollen the run down from Keswick went well bloody wet but a good run stopped for fuel and food on the way bike ran like a watch got to the hostel put everything in the drying room we were soaked to the skin
The next morning the bike started fine then cut out dead after about 10 seconds about an hour later i got it started again just soaked everything in wd40 it warmed up fine i rode it round the car park a couple of times all seemed good so i set of home got out of the car park onto the main road 100 yards later it was dead eventually i gave up called recovery 3 hour's later a very nice man turned up got his meters out then rang his mate the phone call went like this yup it primes yup it sparks once yup it fuels once so we won't get it going oh
He then explained that his mate had told him that it's the crank sensor wiring it's the weakest part of the BMW range
Got recovered home pulled off the timing cover and couldn't believe what i saw where the wiring hadn't melted it had gone brittle and was full of cracks and splits
Within a week it was up and running again with the new hall sensor unit from Greece and hasn't missed a beat since

If you have a centre stand or a lift and your bike is dead the test for hall sensor failure is remove the spark plugs ignition on turn the back wheel with the bike in gear make sure the side stand is raised when doing this if you hear the injectors pulse once then nothing your hall sensor unit is shot
The problem being the above test won't show if the unit is failing only that it has failed

Sorry for the long post but hopefully it'll help Dai

[Dai wiskers]

Someone here identified what the sensors were, listed the Radiospares (?) part numbers. They were about £12 each. Of course, I do not have a clue myself what they were.

The correct wiring is the expensive bit there was a fella in the states selling the correct colours in the right lengths but i have lost his name and address

[Dai wiskers]

Founded a good thread from America with pictures that work my computers stuffed so i can't put up pic's

Anyway here it http://forums.bmwmoal.org/showthread.ph ... or-Failure


Edit and anotherhttp://www.advrider.com/forums/s ... p?t=688232

Note Steptoe's link in my signature is now working

[Dai wiskers]

After doing lot's of searching i have found another possible cause for both these bikes problems
The hall sensor plate could be loose allowing the ignition timing and fuel timing to go all to cock but still allowing the bike to run

If you Google BMW AND hall sensor failure you will find many pages

[bricking it]

Thanks Dai and Steve for the info on the hall sensor.

What i have got at the moment is no power at all.

I am thinking ignition lock, battery terminals, big power cable chafed/earthed or main fuse or something like that.

The neutral light started to flicker at the traffic lights this morning, the engine note dipped too, then death ! No lights, no fuel pump, no electrics, nothing. So need to fix that first before looking at what the other problem might be.

[oyster]

Try checking the wires into the base of the ignition switch, not unusual for them to break there.

[nige1200s]

My 1100s did something similar. I noticed that the power came and went as I turned the bars. I found that the power cable to the ignition switch had broken. There is a small grub screw that holds the switch to the bottom of the key barrel. It was dead easy to solder the wire back on the switch and all was well. Worth a look in case it's your problem

[bricking it]

Yep. Ignition switch just needed copious lubing. Now back to the original problem ....

[bricking it]

I dont know what was wrong with it, but its nowhere near as bad now. Still misfires a little on start up and around 2000 rpm, but I'll leave it alone for now.