Completed a cafe racer build on my 1980 KZ650F last summer. Has fired up first time for the past year with virtually zero delay. Always runs great. I was driving to my office the other day and it started sputtering and quickly died. I thought I was out of gas so after pushing to the station and filling it made no difference. I could get some occasional cylinders to fire but nothing serious. Trailered home after failing to resurrect in the parking lot.
So I’ve been going through everything I can think of. Currently I’ve done the following:
Fuel Supply
-Cleaned carbs - still all clean (only run ethanol free)
-Messed with idle screw positions
-Removed pods and used starting fluid
Spark:
-Adjusted timing
-4 new plugs (be7s)
-Replaced both ignition coils
-All 3 fuses are intact
-Tested spark against engine block, all 4 produce bright spark
Compression:
-All 4 cylinders measure 150psi, +- 5 psi
-Haven’t torn into the engine yet but last year I adjusted valve shims. Have only ridden about 1000 miles since
So I’m kinda out of ideas. I thought I knew this bike, inside and out. Not really sure where to go from here. Just tested with starter fluid again after doing all of this. Does anyone have any other ideas on what could possibly be wrong. I’m no longer getting any hints of ignition out of it. Fresh strong battery as well.
Thanks in advance (pic for attention)