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Hello All

I have got a problem with my 53 Twinspark R1100s

Around 2000 revs on opening throttle the engine will cut out / stutter/ not accelerate.

It has been recently been serviced fully - new filters, plugs, valves checked, throttles balanced. It had new stick coils at 40000 miles

Apart from that its fine, 68000 miles on the clock.

Any ideas what to check? I am thinking electrical but dont know really. Hall sensor ? not sure what the symptoms of that packing up are?

I had this, I unplugged the lambda sensor and cat code plug and it sorted it. Bike runs much better low down too.

Sounds like a crank position sensor if the engine cuts completely.

Unplug the O2 sensor and see how it gets on, but this sounds more like ignition to me.

Ok gents
I will pull some plugs and report back. Thanks for the advice.

Seems similar to my prob:-
viewtopic.php?t=15099

Am waiting on new HT leads from eBay, But will check O2 sensor as well.

bricking it wrote:Hello All

It had new stick coils at 40000 miles

Apart from that its fine, 68000 miles on the clock.

?

It could be a coil.....

I have considered the sensible thing this morning - go and try to fix the bike.

However, the weather is too nice, it will have to wait

i have had a bit of a head scratch today and played a bit. There is definitely a misfire during warm up on the rh cylinder lasting 1 to 2 seconds. Its possible to see the intake pipe to the cylinder chugging and vibrating.

Tickover is lumpy, pick up from idle is lethargic and lumpy.

I took off one stick coil in turn with the engine running, the engine runs rough but ok, sounds the same when i did this each side.

So i suspect the RH stick coil. Will test again by removing lower plug leads then seeing how it runs, then remove both side's upper stick coils in turn to identify which one - or both are the problem.

At least thats the plan....

Having done all the above in my last post, i couldn't find any problem. Put it back together and could not replicate the fault.

That was during the week.

So today I wheeled it out of the garage, started it up and it spluttered and cut out again while warming up on fast idle. Same as before.

Having waited for the hottest part of the day i decided to go and road test it for an hour in full leathers (bit sweaty)

It runs fine at high engine speeds, quite sweetly. In fact all engine speeds above 3000 rpm. Got back and idle is fine too. Still think it may be a coil on the way out but cannot be fuel related surely.

last time i had a coil go it did exactly as you describe...

this was individual stick coils on a IL4, mind you, but the principal is the same.

And.....

This morning on the way to work it cut out. Dead, no power anywhere

Haynes Manual out when I get home then.

Get recovered ok?
Let me know if you find owt helpful in the Haynes, I replaced my coil and HTs at the weekend, still the same

Pushed it home half a mile, in full kit of course. Fun

I will post up what i find out

Sounds like the hall sensor wiring to me it's not a cheap job if you use BMW bits but there's a fella on ebay doing a good replacement if i remember correctly he's from Greece i got mine within a week he does both types give him your frame number and he will send you the right one
Dan Cata also does replacement one's but i think they are on a exchange unit you send him your one he sends you a reconditioned one look in my signature for details

The wiring insulation breaks down causing the ignition unit to spark at odd times when it goes completely you will get one spark and the fuel pump will prime as usual but will only send one shot through the injectors

The reason i think it's the hall sensor is the fact that before it goes completely the wiring insulation will go brittle and crack allowing the odd pulse to go to earth causing the ignition timing to go out and it will do the same to the fueling

Hoss i sent you a pm with Steptoe's contact details

Have a look in my signature you will find Dan Cata's email ask him and Steptoe what they think

Hope you get them sorted Dai

Dai wiskers wrote:Sounds like the hall sensor wiring to me it's not a cheap job if you use BMW bits but there's a fella on ebay doing a good replacement if i remember correctly he's from Greece i got mine within a week he does both types give him your frame number and he will send you the right one
Dan Cata also does replacement one's but i think they are on a exchange unit you send him your one he sends you a reconditioned one look in my signature for details

The wiring insulation breaks down causing the ignition unit to spark at odd times when it goes completely you will get one spark and the fuel pump will prime as usual but will only send one shot through the injectors

The reason i think it's the hall sensor is the fact that before it goes completely the wiring insulation will go brittle and crack allowing the odd pulse to go to earth causing the ignition timing to go out and it will do the same to the fueling

Hoss i sent you a pm with Steptoe's contact details

Have a look in my signature you will find Dan Cata's email ask him and Steptoe what they think

Hope you get them sorted Dai

this one Dai?

http://www.ebay.co.uk/itm/Bmw-hall-sens ... 19defdb93d