Hi guys
After reading through quite a lot starting/stalling topics here on the forum, without solving my specific issue, I hope that it is ok that I started my own... :)
I recently bought a 1983 K100RT with 75k km on it. I picked it up 200 km from home, and drove it back with no issues what so ever. I am currently in the process of stripping the bike down, as I would like to put a custom touch to it.
Intentionally, I think I will avoid using the word "cafe racer" as I am afraid of scare some of the bright K-brainiacs in here, away... well.. I just did..
Anyway... So far I have removed the fairings and installed clip ons, new headlight, and front LED blinkers. I actually did the blinker relay hack yesterday, to avoid hyperflashing..amazing what you can find in here!
[size=78%]I have only managed to drive a couple of trips on it, untill it recently began to stall after only a few minutes of driving. [/size]The first time I experienced this, whas when I took off for a test drive around the block, without the OEM speedo cluster. I knew that the accumulator needs the cluster to charge the battery, but I thought that it would be fine for just a small trip.
The bike stalled at the first intersection during idle, and I was able to start it up right after. I limped home where it stalled a couple of times.
Thinking that this surely was because of the alternator not charging the battery, I put the cluster back on and took it out for a new drive. The same thing happened, it stalled after only a few minutes driving, and so I limped my way back home.
When I came back I could not even get it to start. When left over night it would start the first time and then stall, and not being able to start it without letting it sit for 10 minutes or so.
I then red a bunch of topics in here and on the K100 forum, about starting issues. I have tried to follow this guide:
http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htmDuring installation of new handle bars, I disassembled the throttle assembly, cleaned it and put it back together. The symptoms started after this, could be a coencidence.
Things i have tried/leaned/tested so far, to resolve the problem:
Cleaned all ground connectors
Checked fuses
Change fuel filter
Change spark plugs
Switch load shed relay with horn relay
Put contact cleaner in female connector of the EFI
Put contact cleaner in female connector of the electronic egnition unit
Tried to start with and without the TPS (Throttle position sensor/idle switch)
Tried to start without the vaccuum pipe connected to the end of the fuel rail (at the 4th cylinder).
Checked that injectors have a recistance of 16 ohms.
Fuel pump is starting when start button is pushed. I disconnected the fuel line at the fuel rail and confirmed that fuel is coming from the pump.
The Hall sensor is being fed 12v during start attempt at the connector under the tank.
Water temperature sensor giving correct resistance (ohm) at room temperature (cold bike, indoor, 20 deg celcius).
Air temperature sensor giving correct resistance (ohm) at room temperature (cold bike, indoor, 20 deg celcius).
3rd gear rool back magic trick
Battery reads 13v +
I checked that the spark plugs fires, which they do when I initially try to start it. Sencond try, 5 secs later, they do not give spark.
Also, the Halls sensors has come up in alot of the start/stall related topics, and hence I have investigated that as well. When I removed the Hall sensor, the disc/cup that is attached to the shaft,
was loose and I tightened the three bolts. I could wiggle the cup/disc from side to side, before tightening the screws. The symptoms started before I fixed this, and did not help.
It seemed as if there were wear marks on the disc where the Hall sensors are mounted.
After spending three days of testing and error seeking, it finally started yesterday after I cleaned the contact to the Hall sensor. Took it for a spin, and after 3 minutes of driving it stalled again, the same way as before.
The stalling happenes both at idle, low and high revs.
I have not yet tested the Hall sesor, and before doing so, I will try to see if I can test the cables that are attached to it.
If any of you have suggestions as what to try next, I am all ears... Thank you in advance!
PS. I have an okay sense of mechanics and electronics, and as a mechanical engineer I am keen on learning this stuff. I use a Agilent U1253A OLED handheld multimeter to test.
Here is a couple of pictures: