How do you know when the auxiliary tank is full? I've used the gas gauge on my 1800 with the CSC kit until it shows full, but when in motion the needle drops down to just above 3/4 full. I must have overfilled it the first time because at least a half gallon of gas poured from the charcoal canister in front. No excess fuel came from the filler tube like it does if you overfill! It would appear that you could fill it just as you would the stock 1800 but I'm afraid of overfilling it again.
As an aside, please: What is considered a normal range with the auxiliary tank, two people, total 350 lbs?