That is SUPER common in marine applications especially. Trapped in the cowl with the inboard, the heat doesn't help. It is mainly from the ethanol in the gas. Sadly, most fuel line is made from a neoprene blend that is very flexible, but not great with ethanol. The fuel sitting in it makes it even worse. The fuel hoses that you can get for outboards with the primer bulb inline are absolutely terrible for hardening like that, getting tiny cracks, and causing all kinds of problems with sucking air and making it seem like your fuel pump is bad. I know its expensive, but braided stainless is the way to go on an inboard setup like that. You can get kits online. I like to use the copper alloy brake line that you can get from any auto parts store and build hardlines for them for as much as i can of the fuel lines, then use braided stainless for the flexible lines. Modern fuel hose and the ethanol blended gasoline are just asking for a fire. On top of that, it looks like thats either a 2 barrel Holley or Motorcraft carb. They are pretty finicky to get tuned for power and proper fuel mixture with ethanol blended fuel. Any older carb is. The higher the ethanol content, the richer the mixture needs to be. The ethanol blended fuel also absorbs water pretty bad, and will turn older carbs to dust as the fuel evaporates out of them. I collect antique chainsaws and that is a super common issue i run into on them when the fuel tanks are an aluminum alloy or magnesium alloy.
That is SUPER common in marine applications especially. Trapped in the cowl with the inboard, the heat doesn't help. It is mainly from the ethanol in the gas. Sadly, most fuel line is made from a neoprene blend that is very flexible, but not great with ethanol. The fuel sitting in it makes it even worse. The fuel hoses that you can get for outboards with the primer bulb inline are absolutely terrible for hardening like that, getting tiny cracks, and causing all kinds of problems with sucking air and making it seem like your fuel pump is bad. I know its expensive, but braided stainless is the way to go on an inboard setup like that. You can get kits online. I like to use the copper alloy brake line that you can get from any auto parts store and build hardlines for them for as much as i can of the fuel lines, then use braided stainless for the flexible lines. Modern fuel hose and the ethanol blended gasoline are just asking for a fire. On top of that, it looks like thats either a 2 barrel Holley or Motorcraft carb. They are pretty finicky to get tuned for power and proper fuel mixture with ethanol blended fuel. Any older carb is. The higher the ethanol content, the richer the mixture needs to be. The ethanol blended fuel also absorbs water pretty bad, and will turn older carbs to dust as the fuel evaporates out of them. I collect antique chainsaws and that is a super common issue i run into on them when the fuel tanks are an aluminum alloy or magnesium alloy.
What's The timing on that is it 10° before top dead center. I have 5.8 cobra
Point number one on distributor at number one cylinder. Adjust the idle to 750 RPM.