Howdy,

For the younger folk who have no clue:

"Double clutching" helps to lessen crunching the gears when shifting a transmission that has no sychronizers. To shift from a lower gear to higher gear, depress the clutch, move the shifter to neutral, release the clutch briefly and reapply it before moving to the next gear. To shift down, move through the same routine but also "goose" the gas pedal in neutral to bring the revs up a bit. Both up and down, the idea is to match the engine speed and transmission speed as closely as you can.

And, that is a good looker you've got the Old Kombi.

I think you may have a combination of factors that individually would not be a problem but altogether create the rough idle when hot. Your fuel line, routed right behind the thermostat housing is picking up heat from the housing. That rear float bowl certainly looks to be very close to the exhaust. Air flow through the engine compartment when stopped will be nonexistant. And finally, today's fuel has alcohol content of no less than 10% in most markets.

Add a little length to the fuel hose from the pump over to the carbs to make it bow up and away from the thermostat housing. Space the carbs out as you plan but also, make a heat shield to mount like the one used on the 122S. Add a little pancake fan somewhere on the fender well to stir the air around the carbs when stopped. Write a nice letter to the EPA thanking them for adding corn squeezin's to our fuel supply.

-sd