G'day Guys,
I'm (still) chasing an overly rich mixture at idle to 1/4 throttle openings. Have checked all the usual things -
1. Float height/fuel levels
2. Ignition timing and spark
3. Valve timing
4. Cleaned out all carb airways - carb cleaner and compressed air
5. Correct pilot jet size
6. Air screw adjustments optimised (about 1.5 turns out)
7. Fuel enrichment circuit (Chokes) closing off completely
Mechanic reckons that jet needles may be too skinny in needle jet and extra fuel is being sucked up through the main jets.
I rebuilt the carbs with kits from Z1 Spares (Australia) replaced all the needles, jets, air-screws, gaskets o-rings.
The jet needles that I took out are stamped "5CN15" - not sure what the new ones currently installed are but will give the "old" ones to mechanic to try. He fitted a set of carbs off another Z1000 which was in the workshop at the time and everything was fine!
(don't know what jet needles these have fitted to them)
My '78 Z1-R is actually fitted with a '79 Z1000 A3 MKII engine and the carbs fitted are 28mm and have airscrews but no fuel screws.
What I need to know is - what is the correct jet needle size for these carbs??
( Service manual says 5CN-12 for 28mm carbs)
Any help would be much appreciated!
Current Project
1968 Norton P11A Desert Sled
Other bike (and daily ride)
2004 Yamaha FZR 600
Previous Bikes
78 Z1-R (resto)
91 Zephyr 750
73 Mach IV (Resto)
78 Z1-R
78 Z1-R (stolen)
76 Z900
76 Z650
73 Mach IV
72 Mach III
