Diagnostic Help Please (aka what a surprise, buggered again)

[RantMachine]

So, the BMW is buggered. Again. Yes, again again. Or again again again. I've lost count, ok?

To set the scene: 25 miles of riding on mixed roads prior to the breakdown, everything from 20mph city streets to the A14. Riding back from the meet at Connington, stopped at my old house to plan a weekend ride up to PeatBogHorror with one of my old housemates. Got on my bike to depart, and the fun began.

Problem 1:

First off, noted that when paddling the bike backwards with the steering at full lock, there is a sensation a bit like I'm rolling it over a never-ending manhole cover. Very small but frequent juddering, most noticeable through the bars but can be felt through the seat too. Not apparent when the front wheel is pointing forwards. Also worth noting that I managed to leave my disc lock on when setting off from Connington... didn't exactly pull away aggressively and no noticeable damage besides a scuff in the paint on my fork leg, but perhaps buggered the disc? Although if a warped disc was the issue I would've thought that it would be a slower pulsing sensation as the bent bit passed between the calipers, rather than constant juddering. Also would've thought that I'd feel a warped disc regardless of the angle of the wheel, rather than just at full lock!

Problem 2:

Eventually figured "well, even if the disc is warped, I still need to get it home to my tools - time to ride it home carefully". Put key in, turned key, usual procedure. Neutral, Oil Pressure, and Coolant Temp lights come on. Once ECU has run diagnostic, coolant temp light switches off indicating the ignition can now be used. At this point the bike would normally start and the oil pressure light would switch off as the oil pump kicks in. Instead... "TICK". Very quiet and soft "tick" sound, just the once, and immediately all the lights go dead, including the headlamp. Initial reaction is "oh bollocks, a fuse has gone". But sometimes this bike is just plain temperamental, so I turn the key to the "off" position then back to "on" to check if it really is a fuse. Lights come on, ECU runs diagnostic, completes diagnostic. Press ignition... "TICK". All lights go off again. Attempt to switch off and on again, this time bike does nothing. Yep, that'll be buggered then. I guess something has shorted itself. Seems odd that I had absolutely no trouble riding up to his house, parked the bike, left it for 5 minutes or so, wheeled it back out onto the road, and then it inexplicably died. Surely I should've had it cut out while I was riding it? Unless maybe it's the wiring to the ignition that is buggered, or something...?

It was pitch black and the garage has no lights, so I'll be back tomorrow to try and look at it properly. In the meanwhile... any thoughts? I guess Problem 2 is just a case of checking the fuses and then checking absolutely everything until I find the buggered wire, then fixing it and replacing the fuse. But if anyone can think of good places to start looking based on the fact that it was riding fine beforehand, I'm all ears. Only other thing that crossed my mind is that the reg/rec could've gone nuts and fried the battery leaving it just enough power to start up the ECU but not nearly enough for the solenoid.

Also, what on earth could be causing Problem 1??? It's the bit where it only does it at full lock that baffles me Almost makes me wonder if the two are related, if a wire is catching somewhere in something and knackering itself while also catching on something to create the juddering feeling.

Oh, and we thought we could hear some kind of high pitch clunking coming from the bike (a bit like the sound of my spring loaded footpegs clicking into place), just when I first take it off the stand and roll it forward or back. The noise then stops until it's been back on the stand. He thinks it's coming from the bottom end, I think it's coming from further back like the suspension linkage or something. Or it could just be the poor tired on sidestand creaking as its relieved of the bike's weight. Will try to work that out tomorrow too.

All in all... f**k IT f**k IT f**k IT f**k IT.

Going there with a bunch of tools and a multimeter tomorrow to try and work it out, but any leads or suggestions in the meanwhile are appreciated.

[RantMachine]

Problem 3:

I was dumb enough to buy this crapbucket in the first place. I stand by the F650 and G650 being great bikes, just... damn, not this particular one.

[RantMachine]

Side note:

"Fire" is not a diagnostic. Cheers though Glorian

[fullscreenaging]

It sounds like it could be steering head or wheel bearings and a dead battery.

[Stu]

I was thinking the same as Deso

[al_stu]

Battery as above. Maybe bad earth? Dodgy connection to starter?

[RantMachine]

Got my tools and multimeter packed for after work, will start by checking those. Would guess that its fried the battery rather than just running out of juice as I've always kept it on the maintenance charger when off the road.

[Joeman]

Lose battery connection or lose earth that need tightening up.

It's connecting just enough for the low current dash lights but not enough for the high current starter motor.

[Steve D]

Front tyre feathered?

[Fozzie]

A judder at full lock could be a steering head bearing issue.

Get the handlebars off, get to the steering bearing locking nut, loosen it right off, then readjust to your bikes manual spec. You will need a C-spanner. And see what happens, it's a free, time consuming but easy trick.

BTW you can ride the bike like this still, it just means it's probably a little bit out of adjustment, the handlebars on the last bike I did a steering bearing change on got very flappy after 1000 miles once the bearings were probably bed in and they caused a loosening. But this can happen throughout the life of the bearing.

Failing that I have had similar caused by a warped disc, smacking a disk lock is no big deal unless you bend the fork and wouldn't be able to cause the issue described just to put your mind at ease. Only did it when I turned the bars full lock left, and later determined the slight movements in the brake line at such lock was causing a tiny bit of braking pressure to be applied, just enough that every notch in the disk was painfully apparent.

Whack a new battery on there, then check the charging levels with a multimeter, which I assume having had a chinese bike you are well versed with now. If it's that just check to make sure it's a dead battery and not a shagged alternator/reg/rec

And for some back info there to set your mind at ease, my old silver Honda CBR600F was a bast*rd for this. Rode it fine all week, did 50 miles one night then stopped in a petrol station. Get on, key on, all ECU checks done, thunderbirds ar...*click* and everything went dead followed by "motherfuckingpieceofshittingjapanesecraphondabastardliarsprickswithshittingdodgyelectrics"

But then it jumped started fine, so do the ecu checks, whack it in 2nd or 3rd with it being a single and try to bump start.

[Mr Fro]

Yep, as everyone has already said...

Before you do the Fozz head bearing thing, check the wheel bearings by grabbing top/bottom and front/back of the wheel and check for play - give it a spin too of you can and listen for grumbling.

Sorry you're having trouble again mate.

[Fozzie]

I'd think wheel bearings too if it did it all the time rather than just when turned full lock.

The bike has done quite a bit of mileage, so might be worth doing the wheel bearings anyway. Fairly easy and cheap to do

[RantMachine]

Great stuff guys, really appreciate all the minds coming together on this The old garage doesn't have lighting so I have to work quickly before the sun sets, so having a clear idea of what I'm checking certainly makes things easier

Once I've stuck a new battery in, what's the best way of checking the alternator/reg/rec? My multimeter skills are shamefully lacking (I can usually achieve what I need to eventually but I'm never too sure), but I can always youtube it

 

You will need a C-spanner.

For any normal and rationally designed bike, yes. But BMW invented their own tool specially for this job and bike that they don't sell to consumers or independent garages, only BMW dealers. Yaaaay BMW! But yeah, I'll have to see what I can bodge. bast*rds do the same thing with the master cylinder rebuild kits but luckily there are aftermarket ones available to the everyday consumer. Take that BMW.

Wheel bearings were done last June, so about 10k ago. Will still check them to be safe. God only knows when the head bearings were last touched

[Fozzie]

Turn the multimeter to the 20 setting in the "V" area for DC. The V will have a solid line with three dots under it sitting next to it indicating DC. Use this one as there are usually two on the multimeter, one for AC and one for DC but DC is usually the only one with a 20 setting. The AC setting is a V with a wavey line next to it.

Here's a helpful website: https://learn.sparkfun.com/tutorials/ho ... ng-voltage

Red on red, black on black for the leads to battery terminal. Measure the reading when the bike is off, and again when it is running.

If you're reading somewhere in the early 13v area when the bike is running, and doesn't shoot up when you rev it, everything is fine and it was a duff battery.

If the reading changes like the wind, is too low, too high, you have a bust reg/rec.

If no reading at all, you may even be getting pure AC straight to the battery

Edit- I'm on a late one, if you do it tonight, FB a pic of what it's doing at various rpms (providing it is the battery) I'm about and can quickly say "yes that looks alright" or "Looks a bit dodgy, check the manual and forum" if you need a quick answer as the light fails.

Edited August 12, 2015 by Fozzie

[RantMachine]

If no reading at all, you may even be getting pure AC straight to the battery

 

And to clarify, because it's always best to assume the worst with my bike...

What would be buggered for this to be the case?

[Fozzie]

Reg/Rec will have totally broken down and pure AC voltage is flowing from your alternator straight to the battery and basically boiling it dry and killing it. It's happened to me once, typical of the Italian 2-stroke I had, always looking to blow *something* up.

As your bike conked out after use, it sounds more like a dodgy battery than a reg/rec going though. When that goes, the lights get dimmer and dimmer. Whereas a battery works until it basically falls off a cliff and can still work once the bike is running, but is not strong enough to provide starting current to the motor.

Your lights will be using very little amps so the battery hasn't died enough to no longer be able to support them, whereas the motor pulls a huge amount for a brief period and literally a few % of performance loss can make the difference between it starting, or a motor stall which is what that click and dead stick is. Basically all the batteries energy is being pulled into the motor circuit but it's not strong enough to start it.

[RantMachine]

Good times!

Managed to find a battery on Amazon marketplace, stupidly difficult to hunt down one of the buggers anywhere else and apparently the only sealed batteries for my bike are available only in the States (and necessitate modifications to the battery tray). Could always send a cheeky email to my other half and ask if she can bring one back with her

[Mr Fro]

The battery specified for your bike is YB12AL-A. Halfords stock the YB12A-A which has the terminals the other way round if the cables will stretch...

[Arwen]

The power issue you have described is more or less the exact same symptoms that my car had, when the earth cable decided it wanted to be free and disconnected itself from the car. AA man very kindly rerouted a new earth cable to another part of the engine bay and it has be absolutely fine since (happened over 2 years ago, still same battery). Not sure if your bike has a similar way of earthing?

No idea about the rest... I'm only just starting to learn bike mechanics

Edit:- Also if you haven't already heard of them, https://www.motorworks.co.uk/vlive/Home/index.php are a great source of BMW parts (new and used). My partner has used them for many of his bikes, phones up and gets exactly what he needs at good prices. They should be able to get you a battery I would image.

[RantMachine]

I'm very familiar with Motorworks, but for some reason it didn't even occur to me to look on there for a battery

They've got a sealed battery available for only £10 more than the Yuasa on I was looking at on Amazon, that'll do nicely

[RantMachine]

Next idiot question:

If it is indeed an earthing problem, how would I identify where the problem is occurring?

I know absolutely piss all about electrical stuff

[Arwen]

Well, when it happened to my car the AA guy put a meter on the battery shock his head and said, yea no earth! So I'm guessing the meter will tell you? (No idea!)

My cable was missing completely, so the guy attach a new one under one of the terminals and then attached the other end to the car chassis.

If your cable is still attached, then possibly it is frayed at some point and no longer acting as a earth? I'm just guessing here

[RantMachine]

Anyone my sort of age may remember the timeless TV classic that was "Prometheus and Bob". I feel very much like Bob in this thread.

[eastanglianbiker]

steering head bearings will not make a clicking sound if bike is moved around on full lock they will make a clicking sound if braking and they have free play in them wheel bearing could click due to weight being on it at a different angle so as others have said get wheel off the floor and check top and bottom for movement on both wheels,also i know you have just replaced it but check drive chain for peace of mind

[Fozzie]

Next idiot question:

If it is indeed an earthing problem, how would I identify where the problem is occurring?

I know absolutely piss all about electrical stuff

 

Blast, I need you sat in front of a white board as a lot of it requires drawings.

Earth just means an equilibrium. Voltage of any kind is created from a difference in electron flow.

You are stood on the earth and have a balance with it, but if you drag your feet on the carpet and get a static shock, that is where you increased your potential difference, and the flow heads towards the easiest path to earth. Usually a zap at your finger as it moves into something very conductive.

In a closed system like a motorbike, the negative terminal of the battery acts as an earth, you may also have various electrical items around the bike with an earth on the frame or engine case. Such as the starter motor.

Basically, look at a wiring diagram for your bike, or send it to me as I have to put up with them all day for work anyway, and identify the earth. Also snap some pics of the starter motor area and I can see the general condition.

Lets get this ol beemer going.