All -- I did some work on my 1992 K100RS a cpl weeks ago. To include: new clutch/spline lube; cam chain followers; new plugs; new bmw plug wires; new fuel filter and tank full lines; sync of throttle bodies; new fluids throughout; new coolant; flushed brake fluid; set engine timing.

The cycle started ok to begin -- brought it home and took it for a longer ride -- as 15-20 miles went by it began to run rough -- adding throttle was met with a slight delay and some surging -- made it home and tried to start it today -- it will not start -- it catches for a cpl beats and then dies -- if I try to add throttle while it is struggling to run the throttle addition immediately kills the engine.

I am lost as to where to go from here and would appreciate any guidance your collective wisdom might offer....

Also -- any good older K bike mechanics in the Indianapolis, IN area you might refer me to...

Thanks for any suggestions,

KJO/Kevin

furthermore --- the fuel pump still powers up when I turn on the ignition...

Generally in situations like this, it's best to look for 'footprints' and by that I mean to retrace your steps and check everything. Assuming all was tickety boo before you started you can be reasonably confident it is related to the work you have undertaken. This might even be something you have removed/released etc in the process of getting to something else. 
I would check the fuel filter and pump to be sure no hose has worked off inside the tank as this is known to happen as the fittings need to be very tight. Did you remove the pump for an inspection of it as well as clean the gauze filter, and check the mounting gasket which is known to perish over time. 
This does sound like a fuel starvation issue so you could also release the fuel hose from the fuel rail and see if fuel comes out when you power up. Are the plug tips dry? If they are sodden wet then the issue is elsewhere
I am sure others will chime in with plenty of advice

Hi I am thinking since it was fine and the performance degraded firstly I would confirm the plugs are the right heat range....if they are and they are wet the fuel flow may be too much ie fuel reg letting 65 psi past instead of 35....or it may be too much resistance in the HT leads..got a multi meter check the resistance.
As you tick these off you will be getting closer each time.

It may be something as simple as a dry joint in a connection so liberal use of WD40 on areas disconnected...now whats left?...remember you need spark and fuel to run...good luck mate.

you did tighten the reluctor plate screws on the hall effects plate under the timing cover , additionally the 3 screws into the crank end of the timing ....I had one of those screws come loose ...and took out both hall effects sensors almost completely .
much the same diagnosis ...would try to start ...a little later, then lost fuel pump as the other sensor went kaput ( no feedback to the efi computer that the motor was turning  )  

just a suggestion for things to check - test

well....thanks for the responses -- it was a fuel starvation issue -- although there was fuel in the tank, apparently it was inadequate to keep the engine running -- I placed another gallon and the cycle did start up and run better.  (Kind of hate to admit that but in the interest of full disclosure...).

I am now trying to set timing -- I have a timing light and wish to run this by you all -- I think I understand what to do...but...

In reading about setting timing I found that I could use the TDC marks (the arrow and the V notch) and an adjustable timing light to set timing at idle.  I have read somewhere between 4 and 9 degrees btdc is correct at idle -- (I'd love to narrow that down a bit... )

http://www.ibmwr.org/ktech/k-bike-ignition-timing.shtml

http://skylands.ibmwr.org/tom/tech/k75_timing.html

So, I increased the advance on my timing light from 0 to 8 degrees and then adjusted the HES plate to align the arrow and the V notch (should have been at 8 degrees btdc after this maneuver).  Light was reading off of the #1 plug wire.  Idle was at 1000-1100 rpm.

I was hoping to stop there but when I rode the rig I found that I had some detonation so I started trying to move the plate a bit counter clockwise to retard the spark -- then the rig was lurching when throttle was applied and had some popping while trying to drive it (again was not smooth running -- lurched...)

I've stopped there -- perhaps I need to go and adjust timing at full advance (6K rpm..?) and go for 30 degrees at that rpm...?  So, I increase advance from 0 on my light to a reading of 30 and have someone hold the throttle at 6K and adjust the plate to line up the arrow and notch...

Guess I'm asking for some confirmation that my plan sounds correct..and needed...

Thanks for helping a guy out...

also -- fuel hoses are tight in the tank; I did remove the fuel pump and clean the screen and replaced the mounting gasket; 4 Bosch XR7LDC plugs.

Set your timing here like this. Do not use the notch behind the hall sensor plate for timing it is a TDC not an ignition timing mark

Setting the timing by aligning these marks will make it to within 1° then advance it 3mm on the outside diameter of the plate and that will be 10° BTC the best spot.
You can not accurately use a timing light

Here's some additional discussion of setting the timing using Rick's method described in the prior post.  https://www.k100-forum.com/t548-timing-a-k100-to-find-the-sweet-spot.  

Haven't done the fine-tuning myself, but I did align the notch per Rick's picture above when installing a new HES unit and the bike runs quite well just doing that.  Will likely tweak it for the "sweet spot" when I have a bit of time to mess around with it.

Again -- thanks all and Rick...

The looks pretty simple..

Kevin

For those following along Rick's suggestion has helped a lot -- much smoother...

Still a little hesitation sometimes and occasional bits of roughness but way better....thanks, again.

Another question re syncing throttle housing butterfly's -- 

It looks to me like the fuel pressure regulator vacuum hose comes off of the #1 throttle body (T's into it's vacuum fitting).  I have a "Harmonizer" (see Advrider.com forums) a 2 port digital balancing meter (as opposed to a mercury manometer).  If any of you are familiar I would like to run what I think I need to do by you and see if it sounds correct. (..or, if you are a merc manometer guy just substitute a 2 port manometer and follow along...).

I'll attach the harmonizer to the #1 throttle body vac port with the pressure reg T'd into it...I will adjust the bypass screw to get the highest vacuum reading.  Then, using the #1 TB as the reference I will attach the second line of the harmonizer to the #2 TB and adjust it's bypass screw so as to balance with the #1--- balance #3 with #1 and finally #4 with #1.

Just confirming that this technique sounds correct to you...

Again, thanks for the advice

Kevin

I'm not sure about going for the highest vacuum reading.  I do mine by going in to lightly bottom the air screw and then backing out about 1 1/2 turns.  Then I balance the rest of the throttle bodies to that one.  Should give a hot engine idle rpm of about 950 to 1000 when you are done.

Thanks for the comment -- need to know that keeping the rule regulator vac line T'd into TB #1 is the correct thing to do?

Kevin

possibly better off to start at number 3  which is the throttle body that works directly off the cable ...
you may notice that some of the linkages have crept a little and will not obtain the same vacuum levels as you open the throttle.

so just a little off full vacuum ,,,somewhere about 24 inches / mercury - hg (theoretically 27 might be max ) seems to make a good reading across all
to check for the linkages pick 3 and maybe 1  to see what happens at about 2000 revs and test if is any significant differences .( obviously the vacuum will be lower )
as .75 says above ...about 1.5 turns out is good to aim for .....

don't forget that the vacuum settings can be affected by shim adjustment ...ie too tight wont let it achieve the best it could be, as the valve might be slightly open at running temperature . ..exhaust valves/seats  are prone to burning also if shim gap is left too tight ...regression is noted amongst most k100s  over the years . 

keep in mind that many of us have found leakages between the rubber throttle body mount to head rubbers ...and also the above tb rubbers ..which are known to deteriorate over the years which also could affect the readings .

good luck
hope some of this helps

just make sure that all the regulator lines are good and no leakage ...and the throttle body take offs  not connected to the guage are capped with a good ...not fractured rubber cap ...they are cheap and easy to replace  from most auto stores and are also known to be found cracked and leaky .