Im really digging my 16v K just lately. Ive been telling everyone at work how despite it being 25 years old, its still dead reliable. Now it seems it's just dead .

Had a great run out on it this morning, around 70 miles before I got in to work this afternoon. After I came out of work about 6 hours later the bugger wouldn't start. Here's what I can tell you...

As soon as I turn the key & the dash lights come on, the fan kicks in (never had that before) and it simply refuses to turn over.

Also (and I don't know if this is relevant), if I try putting it in gear with the clutch in, it doesn't turn over.

The battery is a brand new Mottobatt 30ha, so I know that's ok.

Any ideas?

Is the starter relay clicking?  How many miles on the bike?

No clicking, just the usual fuel pump whirring when the key turns, and a healthy turn over on the button - just not firing. Its similar to when you try to start it with the side stand down.

I mentioned the fan, as that is definitely unusual. It's roaring once the key's turned.

Done 54,000 miles.

Could be the temperature sensor, Bonzo, if it thinks the engine is too hot it'll turn on the fan but won't allow the engine to start.

Paul.

Or, taking Sidecar Paul's comment, the connection to the sensor or the washer under the sensor. There is a thread on that but removal and cleaning washer and refitting might sort it. I have a suspicion though that 'remove it' means strip fairing panels and radiator off.

Temperature sensor. Hmm, that makes sense.

Strange how things just 'go' isn't it. No warning. At least it didn't happen this morning 30 odd miles away & work to get to.

Ill have a look at my Clymer manual.

Thanks guys.

If it's the same as an 8 valve    then the resistance of the water temperature sensor at 20ºC is 2.5 K ohms, dropping to 300 ohms at 80ºC. 'Overheating circumstances' would read below 300 ohms. Maybe a short in the wiring somewhere?

Worth checking for a start.

Paul.

Hello.
Some years ago I had the same problem as you. Check all the ground points. See my post on Eletrical part and the post is called ''she goes crazy-help me'' it was on 

Fri Nov 20, 2009 6:45 pm.

Good luck I hope you can solve your problem as I did!

92KK 84WW Olaf wrote:Or, taking Sidecar Paul's comment, the connection to the sensor or the washer under the sensor. There is a thread on that but removal and cleaning washer and refitting might sort it. I have a suspicion though that 'remove it' means strip fairing panels and radiator off.

You're right Olaf. It means taking off the entire airbox to get at it.

A word of warning from an idiot. Don't unscrew the sensor until you have emptied the radiator.

sidecar paul wrote:Could be the temperature sensor, Bonzo, if it thinks the engine is too hot it'll turn on the fan but won't allow the engine to start.

Paul.

+1 
Also check the wire for a short to earth as that will have the same effect.

RicK G wrote:

sidecar paul wrote:Could be the temperature sensor, Bonzo, if it thinks the engine is too hot it'll turn on the fan but won't allow the engine to start.

Paul.

+1 
Also check the wire for a short to earth as that will have the same effect.

Cheers for all your help folks. First job is to get the bike back home to check it over - hope to recover it over the weekend.


Rick, forgive my ignorance, which wire to earth? Is there a wire coming direct from the temp sensor to earth?

If the wire to the sensor from the ECU is damaged and touching the frame it will make the ECU think the engine is overheated and over 113°C the ECU will prevent it starting by cutting the injectors.

Ahh, gotcha.

Many thanks Rick (and everyone)

Just to add to the advice above... Measure the resistance on pin#10 to earth on the FICU plug (under the seat). If its 0.5 ohms or less its most probably a short in the wire. If there's some resistance there then its likely to be a faulty sensor (measure when the engine is cold you'll have the best chance of getting a meaningfull reading if the sensor is faulty). 
That will give you a place to start looking before going to the trouble of taking the fairing off to get to the sensor.
Instructions here about 3/4 way down the page.

If it looks like its shorting, disconnect the sensor plug and test again. Short- its the wire. No short- its the sensor shorting out

I recovered the bike this morning. I pushed it probably just shy of 2 miles and now 5 hours later I can hardly type. I feel like my arms are falling off! I cant believe how a very slight incline can hurt so much  


Anyway, I can relax a bit now as it's back in the garage. I knew I had a full day ahead of family stuff so wouldn't get chance to get stuck in but I did give it a look over. I noticed that the level was low in the recovery tank. Not empty - just down to the min level. I topped that up.

I unclipped the connector from the Motronic unit and clipped it back in, just in case there was any damp in there (its been outside for a couple of nights in the rain) and tried the ignition again. No fan. It started first time.

So, on one hand I'm happy its going again, but on the other, I don't know what was happening.

Why would disconnecting the plug & then re-connecting it make it work again?

Also I need to ask another (possibly related) question. As my abs is faulty and discharging the battery I disconnected the unit leaving the plug dangling. Is this OK to do that until I can get the abs unit sorted? Does that affect anything else other than the brakes?  As far as I can tell the only difference (apart from obviously having no abs) is a red light on the dash.

It is quite possible that the Motronic connector was the problem and that cycling the connection made it work again.  Have you sprayed the contacts with DeOxit?  If you don't have any, it is a good idea to get some and begin a program of systematically going through all the connections on the bike.

It would still be a good idea to go through checking the temperature sensor and it's wiring, as there may well be an intermittent problem there.  A thorough check will be a confidence builder.

That is a very common problem with those connectors so I would say you can relax a bit.
A good idea is to get some deoxit (contact cleaner not like WD40) and go ove every connector you can find, it will pay dividends.
The contacts don't have very much tension on them so a small bit of dirt will create havoc.
Keep an eye on things still, you will always need to give them a bit more TLC than a new bike but they are worth it and it is supprising how reliable they are compared with many other brands of the same age.

I know lots of you guys recommend DeOxit, I just cant find it in the Isle of Man & getting it posted over is a bit of a nightmare. Next time Im in the UK Ill try to get hold of some.

Ive cleaned the connectors with an electrical contact cleaner that I have (Wynn's) and coated them with a silicone grease, so it should be OK.

Yep, assuming it carries on running all will be fine & Ill go to work on the wiring, ground & connections over the winter.

The ABS. Is it ok to run without the unit connected?

Cheers all

Bonz

Bonzo--De oxit D5 is available on Amazon UK, £22.75 a can and well worth it.

Yeah Gordon, I spotted it. Sadly as its aerosol they won't ship it out of the mainland 

Nightmare.

Sorry for delay, can't help as not coming over until the Manx next year. Know any body in the Pool or on the ferry?

Gordon Smith wrote:Sorry for delay, can't help as not coming over until the Manx next year. Know any body in the Pool or on the ferry?

Actually I've just realised, my youngest is going back to the motherland in the next few weeks. I'll get Amazon to deliver it to our mates house where he'll be staying.

Sorted! 

"The ABS. Is it ok to run without the unit connected"
That is what the guru recommends if it has a fault and isnt working.
http://bmwk10075abs1fix.web.fc2.com/

Hi guys
I had a similar problem today, left the house to get petrol no problem starting got to garage about two miles away, got petrol and when I tried to start the bike nothing not a turn over nothing dead. I wondered had I done something when filling up. Tried to start blke on and off for about ten minutes, checking any wires I could get at etc. I did notice when I turned key on the dash lights came on, indicators worked break lights OK but the dip lights or head lights would not come on. Called breakdown recovery had a chat with a good Samaritan on a varadero while we waited then I turned key pressed starter and hey presto she started weird or what. Any ideas what might cause this, was it battery or what.

Cheers.

My guess would be the starter brushes.  The headlight not working is a clue for this.  The headlight could have been off because of the "load shed relay".  The load shed relay could have been off because of the starter brushes.  The next time  this happens (and it will if it is the starter brushes) try putting the bike in gear and rolling it backwards.  This causes the starter to spin and will sometimes get you a good enough contact between your brushes and commutator for the starter to work at least temporarily. You could also try tapping on the starter.  When the headlight comes on the starter will work.

Thanks Kioolt
Will have a look at that tomorrow and let you know how I get on.

Cheers.

Check this out.  It explains it better then I can.

http://skylands.ibmwr.org/tom/tech/starter.html

Thanks for that very in depth instructions, hopefully. I can follow them correctly.

Cheers

Be a bit cautious about tapping the starter as the magnets are glewed to the case and can come loose or crack and loose the magnetism. The plastic end of a screwdriver would be all that,s needed.

Good point on the tapping lightly.  I was a troubleshooter electrician at an industrial plant.  I got called to a machine that wasn't working right and found that there was a bad sensor on it.  I also found that if I lightly tapped it with the handle of my screwdriver while holding it only with two fingers on the blade that the sensor would work.  Since I didn't have a replacement sensor I told the operator to tap it if it quit working until we could get a replacement sensor.  I got called again about 30 minutes later and the sensor was destroyed.  The operator replied that he tapped it like he saw me tap it.

Honest I only hit it with my hand. Those ball pein knuckles can do a lot of damage.

I have had this problem with both my K100RS and K75RT. I was out and about then the issue presented itself.
What i did was put it in gear and rock the bike back and forth a little and that helped start the bike up.

I ran it for a while before having time to strip and clean the started.

My brother lives over on Isle of Man. Next time you see an S1000RR streaking past it may be him....He doesn't do 'pipe and slippers bikes' as he calls them.

Just closing this off.

Since I disconnected / connected the Motronic plug, all has been well - very happy to report (probably cursed it now ☺)

Thanks again for all your suggestions folks.