"10 or 15 years ago I spoke with a gentleman named Mike Brown who then (probably still does) had the patent rights to manufacture the Fish carburetor. He told me, and no one can likely dispute this, that neither he nor Mr. Fish EVER made the outrageous economy claims that have been bandied about concerning the Fish carburetor."
JW, gotta call ya on this one, at least a little bit. Admittedly, you don't define "outrageous", and the info I got doesn't make specific mileage claims, outrageous or otherwise.
Just got in the mail today some documents I got off e-bay on the fish carb. One is a brochure for the original 'fish' carb, and includes a letter inviting the reader to be an "Emmissary"; basically, multi-level marketing. You try out the product, and if your "sold", you get a salesmans kit to sell to others.On the front of the brochure, it does say;
MORE POWER-MORE MILEAGE-UNIFORM PEAK EFFICIENCY.
"After studying the phantom photo of the Fish carburetor, it is easy to understand why it gets more power and greater mileage out of the fuel used through the entire range of the motor."
In the salesmans kit, he has another of his inventions, actually a great idea;Its called a Fish Mileage Tester. Its a transparent container which holds 1/10th of a gallon,, and has suction cups to mount it to any smooth surface. It has tubing, and a little valve.
"Mileage tester is automatically filled from gas tank.Speedometer reading (actually, I think it really means Odometer)is taken when gas reaches "Start".When gas drops to (2) on scale operator again reads speedometer....If car has travelled two-tenths of a mile on one-hundredth gallon of gas, mileage rate would be 20 miles per gallon."
2 of these are included in the salesmans kit. Overall, as I said, he doesn't make outrageous claims, but its obvious that he's saying his carb will get better mileage than stock ones.
The second brochure is from the "WHITE EAGLE" co. on accesories for the Brown (Fish) carburetor. Says in part; "We handle the popular Fish carburetor which has been reinvented by Mike Brown. You can purchase this item directly from the Brown carburetor co. (address included) or from us. Either way, you will protect yourself from the high cost of gasoline and allow yourself to operate on alternate fuels plus contribute to a cleaner environment."
Maybe Mike Brown had no control over what White Eagle was saying, but it sounds like they were an "authorised distributor", and while they were making specific claims, they were definetly marketing it based on economy. I assume the reference to alternate fuels refers to the claim I've heard that with a Fish carb, you could run your car on kerosene. I don't think they had ethanol or E85 then, although theres no date on the brochure.Maybe by the time you talked with him, he had gotten frustrated with people who thought it was gonna give them 100 mpg, when it was (maybe) giving a 10-15% improvement. And, in fact, he may have gotten tired of the whole thing.
Neither brochure makes specific claims, and I'm sure after the postal service business Mr. Fish had, both he and Brown were very careful NOT to make specific claims, in order to avoid charges of fraud.
Still, theres a gray area between salesmanship and fraud, and if with a wink and a nod you allow the customer to believe what they want to believe, well,...Something like "Look, I'm not gonna stand here and tell ya you'll get 100mpg! If I did, and you only got 80, you could have me charged with fraud, and thrown in Jail! It will definetly improve your mileage, try it and see." Leading someone who's gullible, and foolish, to think they might get 80, especially if you wink or raise your eybrows when you say "80". Anyway, not wanting to start an argument.

Jim