The Flamethrower is arguably one of the most powerful weapons in the game. It is only available to Director's Cut members. The flamethrower is one of the only two weapons in Stick RPG 2 that you must build from
scavenged parts from around Paper Thin City.
To complete this mission you need Director's Cut.
Before everything make sure you have 2065$ (1032$ with cheats).
First of all, you have to find Pyro Perry - he is on the 4th island near The New Abandoned Warehouse. Then you have to buy a Leafblower in Hardware store. It costs you 1900$ (950$ with cheats). After that you have to give it to Perry. Afterwards he will ask you for 40oz drink. It's being sold in Seven Eleven and it costs 90$ (45$ with cheats). Bring it again to Perry. The last thing he needs is a lighter - you can buy it at STEEL & HAWK, next to Wallymart. Now you have to spend 75$ on it (37$ with cheats). Once you brought it to him you will get the Homebrew Flamethrower. This is the Level One Flamethrower.
For the level 2 of the Flamethrower, you need only 65$ (32$ with cheats).
the first thing you have to do is to win a fight in Sewer Dungeon - it will give you the required Fuel Cell. Secondly you will need a Cheap Watch and a Screwdriver. To get the first one, you have to defeat a Sewer Person at night or "max out" job at New Lines inc. Lastly you will need a screwdriver - you can buy it at Hardware store for 65$ (32$ with cheats) or obtain this from a hungry Sewer Person sitting next to U of S at night by giving him an Old Hotdog. Once you give these items to Perry - the Level 2 Flamethrower is yours.
Make sure you have at least 95,500$ (or 47,750$ with cheats).
The last upgrade, Level 3 requires winning a fight in New abandoned Warehouse. Once you kill everyone there, you will receive a Hyper Drive (note: this is also required to help the Alien next to the castle). Hand it to Perry. Then you will have to win the fight again, obviously after 7 days. Give Hyper Drive to the Alien and he will ask you for Programmable Nanobots - to get this item, you have to enter the Benjmamin's club (Benjamin's Club Card required, it costs you 50'000$ or 25'000$ with cheats! You can get it in ) and there will be a guy near slots machines at you right after you enter the building - he's a Premium Weapons Dealer and he sells it for 45,500$ (22,750$ with cheats). Hand nanobots to the Alien and he will give you the Solar Matter - one of the last required items to create Nova Flamethrower. the last one is 4D Hypercube. There are couple of ways to receive it - you can either win chess game in U of S (certain intelligence level required), free the Nigerian Prince in prison (10'000$ required) or kill all gangsters in Gangster's HQ. Once you got it and gave it to Perry the best flamethrower is in your hands.