BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down    Cold Start Difficulty on Thu May 24, 2018 9:02 am

Kafflut

avatar
Silver member
Silver member
My 2valve K100 1986 stood unused for about 4 weeks. One of the starter switch wires became undone. A very simple matter to fix once I located the problem.

Before it always started first turn with the fast idle halfway open when cold and first turn, no fast idle encouragement after the engine was warm.

After fixing the starter switch wire it took a number of attempts before I could get the engine running. I tried with the fast idle leaver full, half, closed. Closed seemed best, but then the engine would turn over a few times and stop. After about 5 times it would idle but die when I open the throttle. I had to let it idle for some time before I could get the revs up.

With the fast idle leaver fully open the starter would turn the engine but one could hear it was never going to fire.

Having got the engine running I decided to leave it overnight and try again the next day to see if the cold start difficulty persisted. It did. I got it running again and again left it overnight. Same as before.

The next day I went for a 50km ride after letting the engine warm up.

Since then it has been back to normal, fast idle half open for a cold start and it takes first turn.

I'm curious. I made no adjustments to anything. The battery was not disconnected at any stage. Oh yes, the TPS is disconnected, has been for about 7000 km

http://bmwk100k75.weebly.com/
    

2Back to top Go down    Re: Cold Start Difficulty on Thu May 24, 2018 10:30 am

duck

avatar
Life time member
Life time member
Battery may have been a bit low from sitting and then charged back up when you ran it.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

3Back to top Go down    Re: Cold Start Difficulty on Thu May 24, 2018 12:17 pm

Kafflut

avatar
Silver member
Silver member
@duck wrote:Battery may have been a bit low from sitting and then charged back up when you ran it.

I did not think of that! The thing is I had the battery charger connected to the battery - so at the time of trying to start the bike I ruled out the possibility of low battery. Thank you - Your comment reminded me that yesterday I wanted to use the battery charger and found it not working!

I think that's it as far as struggling to start. But would it explain why the engine died when twisting the throttle before it was warm? Which btw has also changed - I can now twist the fuel open immediately after starting.



Last edited by Kafflut on Thu May 24, 2018 12:22 pm; edited 2 times in total (Reason for editing : Typo)

http://bmwk100k75.weebly.com/
    

4Back to top Go down    Re: Cold Start Difficulty on Thu May 24, 2018 8:49 pm

RicK G

avatar
VIP
VIP
The K100 I had and the current K75 are like that. I have just learned to accept it and ride them more.


__________________________________________________
"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats." from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

5Back to top Go down    Re: Cold Start Difficulty on Wed May 30, 2018 4:27 pm

ReneZ

avatar
Life time member
Life time member
"The next day I went for a 50km ride after letting the engine warm up."

I hope that doesn't mean you let the bike idle until earmed up, as that will ruin the battery and engine in the long run. As the cooling water and lub oil pumps are shaft driven the volume pumped around on idle is limited.

It's better to start the bike and drive off, keeping it civilized initially :-)

Brgds, Rene


__________________________________________________
Greetings from Florida! Having a 'new' K :cyclops: Surprised-o:

Rene


BMW K100 - 1985 (0030029)
BMW K1200GT - 2003 (ZK01223)
    

6Back to top Go down    Re: Cold Start Difficulty on Wed May 30, 2018 6:07 pm

ERasberg

avatar
Silver member
Silver member
I had similar issues this winter with the motorbike taking longer and longer to start (I had to really insist on the starter button for several seconds before it started.) something that got gradually worse.

I got a tip on this site to try and "activate" the fuel pump. A quick tap on the starter button to "charge" the fuelpump, wait 1 second and then try to start. This solved it for me.
Worth a try ?

Lately the bike is now back to its "normal self". And it's "normal self" is exactly the same as what you describe above, with the fast idle half way when cold, no half idle when warm etc.

Other possibilities :
Could it be your fuel pump is at the end of its life and drawing a lot of current ?
Or your fuel filter partially plugged ?

Regards,
Einar.


__________________________________________________
1988 K100 RS SE
97,000 km
VIN# 0146971K100RS
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum