vacuum tanks

Unknown

Tom:

re the vacuum tank and venting. there is a vent hole on the edge of the

lid that

must align with the main housing (the reason for the roll pin on the edge)

so that the lower

chamber can drain into the carb while the upper chamber is refilling from

the fuel tank,

There is a flappper valve in the bottom of the upper tank (the tank that

lifts out) when vacuum

is applied to the upper tank this valve is sucked closed, allowing the upper

tank to draw a vacuum and therefor fuel from the tank, when the upper tank

fills,the float lifts, the springs go over center, and the valve on the

vacuum line trips, closing off the line from the engine (you can hear the

change in engine rpm when this happens). The upper tank then is allowed to

vent to atmosphere and the weight of the gas in the upper tank opens the

flapper valve and the lower chamber refills. Took me years to figgure

this out...If all is working well, you can here the change in engine rpm as

the vacuum tank draws fuel from the tank and then stops drawing , then

starts again. Bill