Old 05-07-2005, 01:30 AM
Big Al-RCU
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Default RE: Can i install a larger fuel tank on a cox .049

Guys, this is a most informative thread. Apparently it is possible to get a consistent run with an external tank. This is not my experience. For example I put a product engine in a rudder only Jr Falcon with a 2 oz round tank. With the needle set as rich as possible and still maintain level flight, it would gradually lean out and fly great for ¾ tank. Then the fun began, it would quit, surge, quit, etc for several minutes til the tank went dry. Imagine just touching down then wide open for a few seconds then quit, then wide open, etc. NOT an acceptable condition. This was a product engine from a Cox Bushmaster plastic C/L plane from the early 70’s. I finally drilled the crankcase for a pressure tap and then did get consistent runs from start to finish. Maybe those product engines had different timing, venturi size or whatever from the baby bees and that made them more sensitive to fuel draw? I’ve been hesitant to try larger external tanks since that experience. Any comments?