Hi brickers :-)
I apologize in advance for this long post :-)
I have having quite a problem with my K100LT 1989 56.000KM.
I bought it a few weeks ago. The former owner has chopped the backend for café racer look. He has also put on a K1100RS exhaust with catalytic converter (Don’t ask me why).
It is running so rich that it won’t run when hot more than 50*C (measured at the water temp sensor). The sparkplugs are completely black. It chops and shoots out smoke.
When I try starting it when it’s cold, it won’t start at first starterbutton press, but it starts at second attempt.
If I unplug the 3 vacuum nipples & the vacuum hose to the FPR, it raises in rpm and it runs smoothly.
I have been through most of “bike won’t start” pdf, and here is things I have tried:
Ground:
Unscrewed the ground connectors under the tank, sanding them with a light sandpaper and put them back on. Unscrewed the ground connection on the gearbox and done the same.
Result = No change.
Clean Jetronic connector:
Result = No change.
Idle switch:
Tried starting the bike without the idle switch connected.
Result = It starts at first starterbutton press.
Fuel filter:
Changed the fuel filter.
Fuel pressure:
Measured the pressure from the gastank to the injector rail.
Result = I think its fine. (I only have a gauge from 0-10psi and one from 50-300psi. But it looks like it’s at about 36psi.
Airflow meter:
Measured at the LE-Jetronic female connector.
Result = Very close or the same at the values in the pdf.
Water temp sensor:
Measured at the LE-Jetronic female connector.
Result = Seems to be the same as the pdf.
Hall sensors:
On a cold engine (not run for 12h) heat up with a hair dryer and start the bike.
Result = No change.
FPR:
While all the vacuum nipples where unplugged I have tried sucking on the vacuum hose to the FPR
Result = Raise in RPM.
I then tried with a big syringe so it was easier to control – I pressed the syringe (Like blowing air into the FPR) = Lower RPM and a lot of smoke.
After this I have not been able to get it to run smoothly again.
- I am thinking a defective FPR? As it might be stuck or running very badly up and down.
Hope you have some ideas :clap:
