Dave105 wrote:
A) My problem is that the choke on the master carb does not open as far as the slave carb choke. Can I simple adjust the rotation of the choke element to compensate for the lower temp? will this force the choke plate open
B) Re-reading Colins how to: do you use the throttle linkage to balance air flow at 2500RPM and the throttle stops to set airflow at idle?
C) One last but not least question, My bus will not start when warm, no matter what I try to do It simply will not start, it turns over but does not even try to catch, while it starts first time when cold, Any ideas will be very welcome
CHOKE OPENING SYNCHRONIZATION
A) There is no "master carb". There is a left carb and a right carb. The central idling circuit has taken up residence on the left carb, but nobody is a master and nobody is a slave in the democratic world of Solex.
To adjust the chokes, you want to find the index marks on the covers and align them with the notch in the upper carburetor boss. THEN you see who opens all the way first. THEN you decide if the late carb is the one to back down or if the early carb needs to brought up. Usually these engines are racing-when-warm, so you want to adjust the late carb to open earlier. Please note, we are talking ONLY about the plates reaching full open at roughly the same time.
FAST IDLE SYNCHRONIZATION
Bentley says adjust the fast idle LINKS with carbs off manifolds, but we can do OK with them on. Cold engine off. Close the chokes with the throttle crossbar slightly pressed open (so you don't bend fast idle cam hardware), then release the crossbar so the throttles are "sitting on" the fast idle cams. Look at the gap between the throttle lever stop screws and the carburetor bodies. The gaps should be similar and generous.
Start engine with air horns and all hoses reinstalled, do not jar the throttle crossbar. You should get immediate light-off and an idle above 2,000 rpm until you blip the accelerator. Then the idle should drop somewhat (this proves that the vacuum break diaphragms are operational).
NOW we can talk about
synchronizing fast idle airflow with the fast idle LINKS. If, with a properly cold engine just started, you get a nice 1,800-2,200 idle that kicks down below 2,000 when you blip the accelerator, the overall adjustment is OK. You can tweak the fast idle LINKS with less than a 1/4 turn on those 9/32" nuts or whatever they are.
But if you want smooth "fuel-injection worthy" cold engine performance, you can synchronize the fast idle links. With a warm engine, take off the air horns and press the cross bar lightly as you close the choke plate only halfway, this will engage the fast idle link. Doing both carbs simultaneously will test your patience, but we want both carbs on the middle step of the fast idle cams. Now use your UniSyn to see which carb is drawing more air. That carb you want to shorten the fast idle link just barely until both are synchronized.
Did you say it will not
run when warm, or it just wont
start when warm? Can you start it cold and keep it runing as it warms up and it will idle when warm as long as it wasn't shut off?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles