Need Help with 18hp B&S

[Al_Smith]

I assume it just has a standard in line fuel filter and if that's the case those can be purchased at about any discount parts store like Autozone ,Parts America etc .You'll about have to tell them exactly what you need it for because if you say a  B and S engine most counter people will give you the deer in the headlights look .

That gunk in the fuel tank could have came from anywhere .Maybe the can you used to dump fuel in for the engine even .If it's in the carb though it could be a reaction between the ethanol laced gasoline and the aluminum of the carb .

Quite frankly I think what you have is typical of a small engine or any engine for that matter which has sat unused for a period of time .My only suggestion is perhaps topping the tank off with gasoline containing  some type of long term stabilizing compound .Of course I may evangilise about it but be fighting the same thing next spring when I get the mower out .I'm not very good at following my own advice or so it seems .