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1Back to top Go down   Headlight Flickering over 4k revs Empty Headlight Flickering over 4k revs Thu Apr 13, 2017 7:33 pm

TheJoker

TheJoker
Silver member
Silver member
Ok I've been experiencing a weird problem and I was wondering if anyone else has come across similar before. Basically when riding at night if I go above 4k revs the headlight starts flickering and the indicators start acting weird. Now however if I keep the bike below this I can ride around with the bike perfectly fine. Also if you are standing the bike still and rev it over 4k the headlight works normally.


I've checked the bulb and that is fine, checked the wiring as much as I can tell can't see anything wrong. Need to make up a new front loom but apart from that it's working fine. Just can't seem to put my finger on it.

If anyone has any idea I'd love to know, here is the bike now it's back on the road.

On that note about the new wiring loom that I'm trying to make does anyone know what the 5 pin connector is called ?

Headlight Flickering over 4k revs 20170410

Headlight Flickering over 4k revs Pixel Headlight Flickering over 4k revs Pixel Headlight Flickering over 4k revs Pixel


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My Bike List past to present so far;

Lexmoto (first bike ever to ride) , CB125 TDC 86 , CG125 89 , GN125 97 , ER5 96 , K100 RS 84

84/01 K100rs 0013627
    

kioolt

kioolt
Silver member
Silver member
I'm thinking it could possibly be your load shed relay turning on and off.  This is usually caused by worn or dirty brushes in the starter.  To test my theory you can turn your key on and lightly tap the starter with a hammer or similar object.  It shouldn't matter if you start the engine or not.  If the light flickers then your starter is probably your problem.  If it is your problem, you will soon be experiencing my starter won't work and my headlight is out problems.


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2004 R1150RT 186,800 miles 
1991 K100LT 128,700 miles
1982 R100RT 106,900 miles
Total 422,400 BMW miles

AMA,BMWRA,BMWMOA


The cheapest thing on a BMW is the nut that connects the handlebars to the seat.
    

BobT

BobT
Life time member
Life time member
The first and most simple thing that anyone would do in this case is to change the headlight bulb and see if it still happens. The second thing would be to check the voltage throughout the rev range.

    

RicK G

RicK G
admin
admin
One thing to check is Does it do the flickering at 400rpm in 4th and 3rd gear. I am inclined to think that it is more the road speed at 4000rpm. As Bob has said the headlight bulb is a good starting point and check for lose connections and bad earths.


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"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

Dai

Dai
Life time member
Life time member
@TheJoker wrote:On that note about the new wiring loom that I'm trying to make does anyone know what the 5 pin connector is called ?
Er - 'five pin connector'? Seriously though, don't bother your head trying to get connectors with exactly the right number of pins. A six-pin would do equally well there.


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1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

TheJoker

TheJoker
Silver member
Silver member
Well the bulb is brand new (just fitted another one and it still does the flickering). I've checked the starter motor and that seems to be fine cleaned it up anyway. With the bike and headlights turned on tapping the starter motor doesn't cause it to flicker. However bushes don't look the best so I've ordered replacement parts to clean it all up. I've also gone around looking at the earths and can't find anything wrong with them cleaned up anyway. Wiring is all fine and secure so not sure exactly what is causing this.

@Dai wrote:
@TheJoker wrote:On that note about the new wiring loom that I'm trying to make does anyone know what the 5 pin connector is called ?
Er - 'five pin connector'? Seriously though, don't bother your head trying to get connectors with exactly the right number of pins. A six-pin would do equally well there.

This is the one I was looking for can't seem to find anything similar either, didn't want to change the connector as that means I've got to mess with the other loom as well.

Headlight Flickering over 4k revs Pin10


__________________________________________________
My Bike List past to present so far;

Lexmoto (first bike ever to ride) , CB125 TDC 86 , CG125 89 , GN125 97 , ER5 96 , K100 RS 84

84/01 K100rs 0013627
    

Dai

Dai
Life time member
Life time member
Not available, unless you pay BMW three mortgages and two chests full of gold doubloons. As for the wiring loom; this topic

https://www.k100-forum.com/t10428-comberjohn-s-ghost

post 9 might be a help.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

KiwiK100

KiwiK100
Gold member
Gold member
Having already been there with all sorts of weird gremlins at play, I'll put my money on a dirty starter motor armature. Eventually the starter will not want to work although a good tap of the starter will coerce it into turning the motor over. 
When dismantling the starter be sure to identify the sequence of the body parts to ensure it goes back together correctly. Get it back to front and the starter spins the wrong way:affraid:


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Current rides:
2002 K1200RS. Owned from new. Pacific Blue, Ohlins, Speiglers, Fiamms, HID. 175,000km
1991 K1. Schwartz metallic black, 18 month frame off restoration. 74,000km SOLD Crying or Very sad
1987 K100RS Style. Black, Ohlins, Race Tech springs, Braided lines. Fully restored. 53,000 miles. SOLD Crying or Very sad
The family history:
1951 AJS 500 single - my Dads ride
1953 Triumph Terrier - my Mum's ride
1916 Triumph Type H, Battle of the Somme, France WW1 - my Grandads ride
    

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