You should have at least a 10 degree angle to the bottle regardless of the brand. You should also verify the siphon tube orientation by removing the valve (after completely emptying it) and adjusting it if needed.
Bill Winters AKA Farmvette
'05 Corvette - Forged 408 Iron Block + TTIX | 980/970 @ 24# : 1120/1100 (150 shot) | 10.15 @ 150 MPH
"When life hands you lemons you upgrade to a C6." - Me