Hi from new member! k75 question
 

Hi I`m a new member !
was just wondering
if anyone can help with with my k75,
I bought a 1991 k75 rt (ex uk policebike) as a winter bike
and with dreams of touring in the summer. It had been unused for two years
before I bought it but from day one it drove perfectly for me. I had all the
usual consumables replaced. Air/oil/fuel filters ,spark plugs etc
and all was well. But after a few months driving I had a problem.
Out of the blue a red hazzard light started flashing on the panel , during
exceleration and braking shortly later followed by a faulty break light.
I took a look at the bulbs on the rear light ,seemed fine.Started the engine
teasted the brakes all seems fine. Put everything back together
left it for another day. Only problem is that now it wont start.
I have used a charger on the battery seems fine.Lights come on
and horn works , all spark plugs spark! but still it wont start.
I think it might be the starter motor.
I`m not a mechanic and have limited experience , thought maybe
someone on this list might be able to help.

Took starter motor out had a look inside cleaned it up a bit but
unsure how to test my theory>

any Help would be great before I tear my hair out!





" Frank Warner
vbmenu_register("postmenu_37600", true); Veteran Traveller WROTE:




Starter motor brushes can get dirty - plays havoc with the electrics as they are used to sense when the starter motor is on "

Youy have to seperate teh problems!

1) bike won't start

2) flashing warning light/brake light...

For 1)
If you operate the kill switch then teh battery/oil warning lights will go out. So that should be the first thing to look at .. also the spark plugs would not spark.

I'd check the side stand switch .. that feeds into the EFI not the ignition so you'd have spark but not fuel? From memory. Could be wrong.

You have spark .. but engine won't start .. start motor turning over .. those are teh conditions I'm working with..
I'd assume you are not geting fuel... you can confirm this .. but it is not eay on an RT .. ruddy flarings ! Pull off the left side lower pane, remove fuel rail - it comes out woith the fuel injectors - clean the recessed are before hand! Now try to start the bike .. there should be a spary of fuel from the injectors .. no fuel = no go. Humm might be esiest to check that the fule pump is running first - check for returning fule back into teh tank as teh start moro is operated .. no return fuel = no go .. is the pump[ actually running? If it is then check the fuel filter.. if not check the relay that drives it . think teh side stand switch come in to play here too.

Enough to be going on with ..

Err on 2)
The flashing was that a regular flashing or intermittant?
If regulaur .. suspect ABS problem!
If intermittant could be brake light or rear tail light .. check for corrosion in the buld holders .. and for a brake in the filiament.

You say you are getting sparks so that means the starter is presumably turning, the ignition is working, the side standswitch, the in-gear switch, even the kill switch are all fine. I suggest you look at the fuel side of things.

An obvious here is, if you removed the tank to get access, did you reconnect the wiring plug beneath the rear on the tank?
Can you hear the fuel pump when you switch on?
Knowledge of the Injection Sysyem is beyond me.

I have found BMW K-Bike Motorcycle Tech Page has a lot of good K series advice. I followed their advice to reset the ABS on 2 Ks. Easy!

If the ABS lights are flashing alternately and don't go out when you get moving (assuming you do get it going!!) try resetting it as they say - but that also happens when the battery is low or weak.

Good luck - let us know how you get on.

Warning - flat battery + starter motor = relay fault!
 

A word of WARNING!!

If the battery goes to a low state of charge .. the starter motor relay can stay ON!!!! It is located under the fuel tank in that big plastic box - hit it hard and you may get it to release. May. If not then undoing the battery ground strap is your easiest alternative - located on the left side - on the gear box about 100 mm above the gear shift leaver entry to the gear box .. I'd recomend a allen headed bolt here - much easier to undo in a hurry (to the sounds of your battery discharging into the starter motor).


-------------------
As I said before .. I think the side stand switch goes to the fuel pump relay (but I could be confusing the Jetronic [K75] with the motronic [4 valve stuff]stuff) .. err as it is 'new' to you .. you haven't been trying to start it with the side stand down (and possibly in gear)? ... [been there, done that.]

----
If the starter motor spins the engine - then it is working .. if it is slugish .. well that is usually the flat battery problem.

k75 help cheers
 

thanks for all the help,
the Starter is off at a specailest to check it over ,
Tried running it off a battery but no luck, it did`nt turn. So now
it`s time to let an expert try.
I re-charged the battery from
a OptiMate Battery charger III SP , all seems fine their, (could be wrong)
My next place to look was fuel injectors but seems like a mine field,
do`nt want to break anything else :nono: Bmw ar`nt cheap bike`s to fix.

I think the flashing brake light and hazzard light problems might be linked to
the starter/battery problem. Both lights falshed under hard exceleration and during breaking or when closing down throtel.
Hopefully when I get starter back I will know for definite if that was hte problem or not..
K75 Battery`s are not as cheap as i thought.

Ben
I'm glad you are making progress.

The starter need not go to a BMW specialist. I have found any reasonable Auto Electricians can check and often repair them. Many items are identical to Bosch parts - the problem is recognising and knowing them.

A K battery is £35 -£50 this side of the water.

Arrr ... That could be the brushes worn out. One wares faster than the other .. undo teh two long screws that hole the starter motor together and you'll find the brushes on the end with teh electrical connection - it will be dirty in there. Clean it up and then look at the brush length .. if it is less than 7? mm then you need to replace teh brushes.. you can get a few more miles out of them by filing the holder so the brushes will fall to the centre. On teh 'new' ones the holder is reversed from the 'older' ones in that teh brushes will fall all the way into the centre .. a pain to assemble .. and when a 'newer' one stops working you have no way of making a tempoary repair..


Yep - bm use it to turn off the load when the starter motor is running .. but 'it' needs the starter motor connected (to ground) to sense this .. some Yes .. can be related.. Especially if the flashing is not regular (like the indicators - they flash regularly).

starter prblem
 

Got the starter back today it works perrectly so I hope this is the problem.
learned a valauble lesson today sometimes BMW new parts are cheaper!

Usually new Bmw Parts cost an arm and a leg but I payed €150.00 (euro)
To have a starter motor expert shop look at it, fair enough they fixed it,
but only moments after picking up the part BMW (Joe Duffy Motors Dublin)
rang to let me know my other parts were ready to collect , so i ask out of interest
how much was a new starter motor and they happly told me €199.00 ,
Shock horror I would have expected €500.00 never thought of asking bmw first. I rang every scrap yard I could thing of but without luck.

lesson learned , always ring BMW first.

fingers crossed when I put the whole lot back in it works.
or it`s €130.00 for a new battery :censored:

cheers for all the help.
I`ll let you know how it goes

BMW Club
 

Ben stop over to The BMW Club :: Index join and have all the bmw info/help U may need.

Oh .... and your so close too


BMW Motorcycle Spares - Motobins Ltd - Welcome

Been using them for years .. good service.. good prices. And from where you are .. you could get the second hand stuff from them?

starter problem
 

Just a quick up date
I put the starter back in and all the other bit`s
and after loads and loads of attempts she started:clap:

The starter was the problem , and she would have started
up after the fix first time only for a loose spark plug lead!
(always check the basic`s)
:thumbup1:

Now she runs but witha very loud knocking noise,
topped up the coolant and oil because they were very low , thinking
the pump was making the sound , but no luck
another days problem