Archive of BMW Motorrad Club Cape (2006 - 2019)

Hey Drew

I had a similar issue a couple of months back.

I completely disconnected the battery for about 10 minutes, and then reconnected it.

The bike then started first time.

It was almost like the computer needed a reset.

Hope this helps!

Cheers 

Hi Cobus

Thank you for your response, I did that yesterday but only took off the positive and all my displays went off. I left it for a while and reconnected but still she didn't want to start.

I will try taking both polls off.

Taking off one pole vs taking off both makes absolutely no difference.  You only need to disconnect one pole from the battery.

Now, rule number two, when disconnecting the battery, always disconnect the negative pole first! This is so that if you accidentally touch the spanner/screwdriver to the pole and the bike bodywork, you won't get a spark/short.

So, all you need to do is disconnect the negative pole for, say, 30 minutes, then see if it makes a difference.

Hi Charles 

Thank you for your response, I went home and tried to start my bike again, it almost sounded like it was going to take and then just turned over.

I disconnected the battery again completely and left it off for about 20 minutes and still it wouldn't start. I will try it again this afternoon for longer.

Hi Drew

What year model is your bike and do you know how old the battery is? I had many different types of issues with my 800GS and most of them were battery related. The 800 is very full of $#it when it come to a faulty battery, causing alot of different symptoms.  Mine did all sort of "funny stuff". Even after charging the battery it would start a couple of times before going bonkers again. The battery just didn't keep its load (voltage) after a charge.

From experience with my bike it can be any of the following stuff.

1.) Side stand switch that is faulty
2.) Faulty clutch switch
3.) Faulty fuel pump or fuel pump electronic (this is the unit under the seat that almost looks like a computers heat sink). Can you hear the fuel pump running when you turn the ignition on?
4.) Faulty Stator, it can cause that the battery doesn't charge properly when riding. You can test the stator and it should have a reading of about 14.6v when the bike is idling.

My best advice is to first take your battery to a battery testing centre so that they can doe a proper load test on the battery. 90% of the time the problem originates from the battery.

I hope that you sort your girl out quickly.

Please don't hesitate to contact me if any of the above is unclear
oh ate too 321 36double2

I agree with Carel, most likely the battery just doesn't have the oomph to crank the engine and keep a high enough voltage for the electronics to run the engine.  If the battery is oldish, just replace it - but have someone charge it to full capacity before you put it in the bike.

Bike batteries take strain due to the vibration of the bike - bits come off the plates and short the plates, leading to a slow discharge and gradual degradation.

Guys, thank you sooo much for trying to help.

My baby is a 2010 model.

I replaced the battery about 8 months ago, because I do short commutes to work I usually charge the battery every 2 weeks. 

I have her charging since about 12 so the battery should be fully charged when I get home, I'll try a couple of starts again and if it still doesn't want to work I'll charge it again and take it to a battery place to test.

Once again I really appreciate all your help.

I had my battery tested at Battery Centre and they say it's 100%.

What ells can I look at, please?

Checked fuses?

Could be fuel pump as well.

Morning Carel

Yesterday I removed the spark plugs after trying to start the bike, I'm going to replace the plugs, but they were dry when I took them out. Shouldn't they be wet? Then maybe it's the pump or electronics like you mentioned.

I saw in one of your other posts you explained how to test, so I will try that this evening. When I switch on the bike I hear the electronic unit peep once then nothing.

Any thoughts would be much appreciated.

Some of the older models were known to have faulty fuel pumps.

Having said this I recon you could have saved yourself a lot of time and frustration by phoning one of the Donfords Service Managers (Shane in CT and Eugene in STB) or one the well known BMW mechanics that have gone out on their own. Alf, Jeandre, Andrew, etc.

They should be able to give you a quick answer.

Rather than all of us "couch mechanics" trying to guess it.

Hi Guys 

First I would like to thank everyone for their help.

Well it turned out to be the Fuel pump electronic modulator.

I tested the pump (you do that by taking the modulator off) then there are 2 pins that you can connect directly to the battery BUT it has to be the  right way round. I got so excited when it didn't work because the pump costs R600 then Carel told me to test again and swap the wires, then it worked. Talking about Carel, he was prepared to drive to my house and take his modulator off and test it on my bike, we have never met and he was prepared to do that, just WOW thank you once again.

I called Andrew at Kingtek to find out if he had a modulator and he said that I must test first to make sure that is the issue because you can't exchange them once it's been used. To test he said that you must connect the fuel pump to the battery so it runs and try and start my bike, which I did and she started.

So, before you strip the bike down, test those 2 things it's easy and quick.

I've decided to bypass the modulator for the time being https://www.youtube.com/watch?v=NgEdEqdcYK0&t=37s so I'm mobile and I can afford the R2400 modulator.

She idles a bit rough and sucking air from somewhere so I'm going to have to take her apart again and find the problem.

Have a great day

Andrew