The Wonderbus is still wanting to stall at the bottom of of downhills. No exhaust leak -- engine dies right quickly when the exhausts are plugged. No discernable intake leak -- sprayed carb cleaner all over the darn place.
One excellent theory for this behavior is carb icing -- not manifold icing -- since I don't yet have the air preheat hooked up to the new-to-me oil bath air cleaner. Another theory which has been suggested is my carb adjusment is off. When the peashooters were off I did notice that they were really black inside -- too rich, right?
I had followed the Bentley's procedure for adjusting this new (aircooled.net) 34 PICT-3 carb previously, so I went through the procedure again with the engine nice and warm (oil temp 150F).
I am not real jazzed about how "squishy" the mixture screw feels. When the instructions call for turning the screw to find max rpms then adjust clockwise until the rpms drop by 20 or 30, it's darn hard to find those points when pressure on the screw from the screwdriver causes the rpms to shift, too. This may simply be a lack of experience.
Got the idle set to 900 rpm, took the Wonderbus for a short cruise. At the bottom of Stall Hill the engine /almost/ stalled, but survived. No after-fires. But by the time got to Sears (9 minute drive) to get a long flat-blade screwdriver to ease my carb adjusting, the idle had dropped to about 500 rpm. Took it back up in the parking lot before heading home. Had to test the screwdriver, y'know.
The carb seems to want to challenge my patience right now.
-- Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus 84 Westphalia: "Mellow Yellow (The Electrical Banana)" KG6RCR