Went on holiday for three weeks and she wont start battery now flat from trying?

[1986 k75s]

Got back from hols wheeled the k75s out of the shed hit the starter button she started up then died . Probably a bit cold me thinks ,tried again huge backfire cloud of greyblue smoke then wouldnt start . Battery now gone flat so removed to charge on motorcycle charger. The plugs were soaked in fuel dried them and cleaned them but still didnt want to start . I notice the buzzing from the fuel pump had stopped the last few tries b4 i removed the battery , just the small backfire .

Was wondering if the fuel pump stops working when the battery gets really low on power ? Fuse hasnt blown that being fuse number 6 in fact no fuses have blown

Bike is a 1986 S model k75 an old dog in reality but with low mileage of 32000 for a 26 year old bike .

Advice please ?  :dunno

[Inge K.]

Since your fuel pump don`t turn anymore, measure if you got voltage at fuse #6 while pushing the starter button.

If you got power, the problem is the fuel pump, tank connector or related wiring.
If you ain`t got power, the problem is the FI relay or related wiring.

Inge K.

[1986 k75s]

Cheers friend i will try that can you explain the trick of reversing the pump to possibly unblock it  ?

[Inge K.]

Reverse the polarity at the pump.

Inge K.

[1986 k75s]

After a good charge on the battery i returned to the bike . I have learned a valuable lesson at this point BMWs are very fussy things for eg dont put the battery back in b4 you put the water filler in eg . A press of the starter and brooooommmm she starts up like nothing was wrong the fuel pump buzzing happily aswell .

So it would appear that a low battery is the cause of my problems and that is all .  :neener: