erratic tickover after new gasket...help

tosh23

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Hi guys and gals,
I ve finished the repair on my 650 (800) to the rocker cover gasket. I put it all back together and now the idle and all rev range is erratic..
Holding the revs at a constant 2k the needle goes from 1800 to 2200 and at idle it is just the same, the needle going up and down.
Ive checked ALL the plumbing twice, Ive had the bike up to full working temperature and still its erratic .Sometimes it backfires lightly and both down pipes get too hot to touch..
Ive had a word with a mechanic friend and he is pointing me to a dodgy spark plug because I haven't started the bike for 5 months,
Im thinking a spark plug cap (coil)...
Can anyone confirm either diagnosis or have any ideas, I know this is very common on a 1150 but searching on here the 800 (650) doesn't have this problem usually.
Cheers guys...Tosh
PS...I read somewhere the spark plug coils are very very delicate and can start to break down if knocked..
 
looking through the last 20 threads it has bought some ideas...mostly petrol..or more specific water in the petrol due to condensation through living In the garage over the last 5 months...

So up to now I have three things to concentrate on. Always do the cheapest things first...
1. drain and change the petrol then run the bike for 10 mins to get rid of the petrol in the feed pipes.... If that doesn't work I still have the old petrol to use...
2. Order new spark plugs, The spark plugs do look old and for £8 it wont hurt at all, the bike has done about 10k I think...
3. Last resort, Ive had a word with motorworks and they guarantee their secondhand parts, A second hand coil cap is £33 .So all in all its not looking too bad upto now.
 
A bit of redex in the tank and/or replace petrol. Take for a run.

I have a feeling these engines don't like to run at around 2k rpm without load.
 
thanks for the ideas guys, I will of coarse let you know the outcome,
At the moment I am waiting for new spark plugs through the post then I will rebuild the bike, to try and get some "good petrol through to the throttle bodies"...
The erratic tickover is also accompanied by some strange whooshes and knocks in the area of the air box and throttle bodies...Doing some research Im going down the route of water at the very bottom of the petrol tank. The tickover and noises are what other people call "pinking" thou' it sounds nothing like pinking on a car engine...
So that's what I will be doing first, I will install the spark plugs, button it back up and run it on tickover for about 10 mins....to try and get new petrol through...
I will report back after this has been done ...

When I was re-installing the rocker gasket I was very careful not to go nuts and rive at things...But I must admit its food for thought, cheers....
Plugs should be here in a couple of days....cheers guys...Tosh
 
I would think the petrol is stale.
I was taught that Unleaded has a shelf life of Three Months.
Syphon the old Fuel out and replace with new, no need to replace the sparkplugs.
 
Dear Stumpy,
Cheers mate, Ive got the spark plugs on order so I may as well use them...
The thing is Ive never changed the fuel on any of the bikes ive had before that have been winterized, I understand that the bmw engine runs very lean to make it very economical perhaps that's why the possibility of stale fuel is at the top of my list...Im just a bit worried about the engine making all that noise and rattling whilst the fresh fuel gets pumped to the throttle bodies..it cant be doing it any good...I did try and remove the 5 month old fuel by way of syphon but there was only 4 ltrs in the tank and I wasn't able to get the tube all the way down to the bottom of the tank .
Anyhoo, cheers for the reply....Tosh
 
Gasket

Hi, sorry i can't offer you any advice on your problem but i had a day working on my bike yesterday and noticed i've got a leak from the rocker gasket L/H/S and just wondered from looking at different threads ranging from refitting the old gasket with sealant/new gasket/modified or later gaskets what you found? regards AL
 
ENA20621 Motorworks part number...
forty four pounds .Its the gasket that bmw should have put on in the first place.. Don't use any old gasket sealant around the half moons, use the right stuff...easy enough to do and if you get stuck just ask on here because they are a great bunch of guys, always willing to share their experience ...tosh
 
update....
I installed the plugs today and buttoned it all up, I also put in 1/4 of a bottle of dry fuel into the tank...
I took the bike down the 10 foot a few times and I still have the same problem....
The bike accelerates brilliantly but de-accelerates with a noise from the air box area, also the hotter the engine got the quicker the engine cut out and when it was at full temperature it wouldn't tickkover at all...
FUEL...
I have made sure the fuel is good....
SPARK...new spark plugs, good battery, engine and ignition timing have not been touched...
AIR...Air box is seated on the throttle bodies, with the 3 other tubes( 2 to the bottom of the throttle bodies and one for the crank case pressure) all present and correct....
So what now ?...
FUEL...possibly fuel pump controller / fuel pump ( don't forget the bike accelerated beautifully)
SPARK...I am waiting on a stick coil from motorworks...anything else ???
AIR...Possible air temperature sensor/air pressure sensor, on de-acceleration there is a very noisy air box/throttle bodies,,,anything else ??
 
Just a side note.....
If it was an air temp/pressure sensor or fuel pump controller then wouldn't it bring up the engine management icon on the computer ???
The engine icon comes on with ignition but goes out on engine start....
Would a 911 help ?
 
The silicon I used for the gasket didn't say "safe for fuel injection systems"..
May mess up the oxygen sensor...As soon as I started the bike I had these symptoms, I take it that the silicon will eventually not immediately mess with the oxygen sensor, Food for thought.....Tosh
 
Update...
I have done a s+it load of research on the o2/lambada sensor/probe and the stick coil I ordered came today...So I left the oem stick coils in and disconnected the o2 sensor,,It back fired a little more and stalled more...
I know the o2 has a heating element inside so after 1 minuite or so the voltage would be 0.2v or there abouts...conclusion- its not the o2/lanbada..
Next I swapped the stick coils from one side to the other and using the known good one from motorworks ...conclusion-its not the stick coils..
Rang motorworks to send the stick coil back and they suggested the regulator/rectifier so checked the voltage across the battery before, during and after start up, values were 12.8, 11.9 and 14.2 respectively so its not the regulator / rectifier ...
Im now thinking of fuel pump control ..there has been a vosa bulletin on the controller for the 800 engine...this is really starting to get me down now...
Anyone with any ideas...Tosh
 
When my 1200 ran like a dog it was due to a secondary coil. I replaced it yet it still wasn't perfect. The rh plug was fouled. My GS911 showed the lambda heater as faulty, swapping lambda probes left/right moved the plug fouling to the lh side confirming the lambda was faulty. I got a new NTK lambda probe from eBay and all was good again, it was about £70 which is half the price of the same part from BMW. I suspect you may have a similar issue, the GS911 lambda trace and fault code reading should help your diagnosis.
 
I hope so, Steve is going to come round next week and have a go at it...
I glad you got yours sorted in the end, I must admit without a diagnosis tool these bikes would be a nightmare...cheers..Tosh
 
Ive had steve come down tonight with his gs-911. We went through the lot and reset everything, check fault codes and reset them. Started the bike with real time window set to the lambda wave and voltage.
When the bike is first started ( when warm) the lambda sends 0.4 volts and then steadily goes down and down, When revved the values go through the roof and then through the floor, there is no steady wave between 0.2v and 0.9v. On tickover it is running really really lean, below 0.2v...
Looks like an o2 sensor is on the cards...I will be on the phone tomorrow with motorworks to order one..Whilst I am waiting I will strip the valve cover off again, clean the gasket and reinstall with o2 safe rtv...
I will keep you all updated and let you know if anything else pops up...Tosh
 
If the lambda voltage reading is changing then the lambda sensor is working.

The reducing voltage reading at idle could be an air leak. Try spraying carb cleaner onto the induction tract between the throttle body and the engine. This will cause a rise in rpm if there is a leak. It will also cause a rise in the lambda voltage.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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