K100 4v '92 long time to ignite & randomly hesitate, stutter, stalls.

[The Mighty Gryphon]

That is great news!  So another ignition switch rears to bite an owner.

I have had problems with that switch in two of four bricks I have owned.  It is now one of the first maintenance items when I purchase a new brick.  There is a reason why that switch is #4 on Johnny's list of major whack sources.
http://www.motobrick.com/index.php/topic,11033.0.html

[LeMoeur]

That is great news!  So another ignition switch rears to bite an owner.

I have had problems with that switch in two of four bricks I have owned.  It is now one of the first maintenance items when I purchase a new brick.  There is a reason why that switch is #4 on Johnny's list of major whack sources.
http://www.motobrick.com/index.php/topic,11033.0.html

Oh, wow i get to see this beautiful post only now!
It came to my attention, while doing this search to track down my problem, is that there’s little to no literature about 4v bikes. And if there, it’s only found fragmented into posts throughout the internet, in various different sites, like bmwoa, k100forum and of course this one.
So for the little but critical differences that our bike has i thought that would be useful to make a pinned post or maybe anoter “Bert Vogel-style” pdf to gather them all (‘and in the darkness bind them’).
If anybody’s interested in the project i’ll be happy to assemble it in my spare time.. so welcome PMs!

[Filmcamera]

I that is a great idea.  I have a 4V bike as well and seem to find more often than not that what applies to a 2V bike does not apply to mine.


For your reference this is a great site K1100 Owners forum it is aimed at K1100's but they are almost identical in most ways to the 16v K100's, certainly more like them than the 2V bike are.

[LeMoeur]

Guys... after all this time i had to finally go and see the mechanic. Only he could do the TB sync i thought needed to do to make things better for my beloved.
So it was, some syncing, some US cleaning for the TBs and a good regulation of the CO2 pot made my bike run sooo much smoother, or at least it can now keep the idle without stalling.
Although there are still a lot of problems..:
1. Stalling when cold if i do a quick twist of the throttle (on closing)
2. Strange “power surge” or “sobbing” whatever it’s called from 2k to 4k RPMs only under load (i mean it doesn’t happen when in neutral)
3. Terrible mileage.. like.. 7,5km/l or.. 4,7mi/l

Things i’ve done.. changing the HT leads to new NGK ones.. while doing that i found the spark plugs to be in bright shape..... [emoji57]



Obviously changing the leads led (pun intended) to nothing.

Now i found this strange plate light behavior:



Any suggestion, Sherlocks?

Thanks as always for your kind collab

[The Mighty Gryphon]

Regarding engine performance: have you checked the engine temperature sensor located behind the radiator?  A bad sensor will lead to a lot of over rich running issues like poor high speed running and poor fuel efficiency.

Flickering light:  I would check/change the bulb and clean the electrical connections behind the taillight assembly.  Engine vibrations are shaking a loose/dirty connection or a damaged filament in the bulb.

[LeMoeur]

Regarding engine performance: have you checked the engine temperature sensor located behind the radiator?  A bad sensor will lead to a lot of over rich running issues like poor high speed running and poor fuel efficiency.

Flickering light:  I would check/change the bulb and clean the electrical connections behind the taillight assembly.  Engine vibrations are shaking a loose/dirty connection or a damaged filament in the bulb.

I’ll be getting new sensors in a week, i’ll then proceed to write here if i find any changes.. i see that they are quite cheap and it’s not bad to have some cool new gear under a classy old lady!

Regarding the flicker.. it’s not the bulb for sure as... it has no bulb, it’s led [emoji12] but i’ll do the connector check thing, thanks. So.. you rough running it’s higly unrelated to this? Because i found that some of the lights started to act strange, and they appear to be in synch with throttle twisting moves.. moreover i had sporadical “no pump priming” issues, that resolved by themselves [emoji848]

[BlitzenGruv]

change the fuel filter make sure the fuel flow directional arrow is pointed in the correct direction.

It seems to be too simple, but check the fuel line from the filter to see if it has swelled. Only replace this line with fuel line designated for immersion in fuel. DO NOT use the line supplied with replacement filters, it will not survive long immersed in gasoline.