earthing fault?

[sidpick]

Hi all!

after the post winter deep clean I'm having a mare getting the bike to start - well, I can't get it to start!

Tank, throttle bodies and exhaust were all removed. Tidied up the wiring from zumo/autocom etc and charged battery on optimate while cleaning all other bits.

Now its all assembled its turning over but not catching, the closest it came to catching it did a mini backfire.

I have set all the cable slack as per the bmw manual, BBS are 1 1/2 turns out everthing I have touched has been checked to make sure its wired up properly and not loose.

Today put a volt meter into the aux power socket and registered 12.9v (straight after removal from optimate)
After pressing the start button the voltage drop went down to something like 7.5v, RID reset and a slow turnover.

Never doing this before (as I've never had this sort of problem!) is this voltage drop likely to be an earthing fault or something more sinister.

It was running fine before the clean up and I've done full services on the bike now for the past 3 odd years without major problems...

I've now removed spark plugs and checked coils, all appear fine and fuel is getting to the tips of the plugs.

Any thoughts out there???? I'm wishing I'd not started this bike cleaning session now....

Thanks in advance for any advice

Sid

 

[John Armstrong]

Checked that the battery connections are clean between the lead / battery post and that they're both tight?

 

[wildbeeste]

I would suspect the battery.
The large voltage drop indicates that not holding charge (failing cells?)
I have a spare (old) battery that you are welcome to try before forking out £100 for a new one.
I am passing Horsham on Monday and Tuesday so can drop it off.

 

[hops]

I would suspect the battery.

Me to, the cold weather will kill a battery that's not in tip-top condition.

 

[Steptoe]

Whhhhhaaaaaaayyyyyy hhhhhhhheeeeeeyyyyy

it must be my turn to post the picture ( i know it says the cable play has been measured, but worth a try)

 

[sidpick]

checked, checked and checked again!!!

Cables are always my first check as they seem so easy to unseat
(and I've always been directed to this problem when problem solving via the site in the past!) There all spot on, the lock nuts are loose though as I was planning to sync the TB's whilst waiting for the oil to get to temperature for the oil/filter change

The terminals were clean and connectors tight,

Fingers crossed battery as suggested, its the original so suppose its probably up for renewal by now!

The only connector I removed (apart from all the tank components) was the lambda sensor, not done this before as I needed to sort out the exhaust / cat, this is re-connected and secured back in the original place.

Nothing else has been played with, just everything has been cleaned..

wildbeeste you have PM! Thank you!!

Further investigation on thursday now...for what its worth! will see if the battery drops again,

Never having to jump start the bike in the past could trying this pin down the dodgy battery giving it the boost to get it started / running

Thanks!

Sid

 

[davegs]

Lesson for today

So now you know NEVER clean your bike!!.
Dave GS

 

[sidpick]

Thanks for all the pointers! Problem now solved.

with the very nice battery wildbeeste provided after a little coaxing my bike fired into life.

Took 6 presses of the starter button but the turn over didn't slow down or get anywhere near the stage or relay chattering.

After a short static run up to 2 bars on the rid I let it cool down.

I know the bike was quite warm but the starting difference was amazing, used to holding the starter for at least a couple of seconds it fired up super quick and it sounded like a bike with purpose

Now the oil's done and most of the bike is back together, just pannier frames and crashbars, one more careful clean up in case I missed anything before.

Think I may have to invest in a different battery charger as my faith in the optimate is gone.

The one thing I have learnt (although I've done it several times, I think the practice has paid off) is that the set up of the cables makes fine tuning a very quick operation. I swapped the cables last year and found when setting the choke it didn't make too much difference and just lived with it. I had a bit of time to kill this time (after checking the seating of the throttle cables for the 10th time!) so I watched what happened when you turn the adaptors on the bars and throttle body cables. Watching them all work together made the final tuning on the carbtune a very easy job. Spot on so well happy.

Bike sounds sweeter then it ever has done now, really quiet, sitting at idle nicely and good pick up.

So thanks again wildbeeste! life saver and thanks for the pointers!

Now time to take it out and get it minging dirty again, M25, 19th December 2009 tried to destroy the bike and me, now its looking like a 'nearly new 55000 mile GS!'

Sid