Four Wheeler's Carburetor Tips

Hose Tech

Sometimes fuel system problems aren't caused by specific components but instead by the hoses that run between them. Most people overlook a fuel hose unless it's leaking, but there are a couple of factors that are important. First and foremost is that hose diameter needs to be large enough to provide a sufficient volume of fuel to the engine. In some extreme cases, a small-diameter hose may cause an insufficient amount to reach the carb. Steel line is more reliable than rubber, but steel hose can transfer heat, while rubber line acts as an insulator. Steel can work-harden and break when exposed to prolonged vibration, but rubber can crack and decay with age. Keep these things in mind when you're routing fuel lines.

The following chart gives you some general guidelines on correct hose diameter and fuel pump volume according to engine horsepower.

Improperly routed fuel lines can cause vapor lock. This rubber fuel line is actually laying across the valve cover, which makes it very hot when the engine is idling. Also, the steel line to the fuel pump was routed between the accessories where engine heat gets trapped.
Improperly routed fuel lines can cause vapor lock. This rubber fuel line is actually layin
Hose diameter is important to consider when performing an engine swap. The 5/16-inch hose (A) is adequate for feeding most four- and six-cylinder engines. The 3/8-inch hose (B) is good for most V-8s, but the 8-inch braided hose (C) should be used on all engines with lots of horsepower.
Hose diameter is important to consider when performing an engine swap. The 5/16-inch hose
Fuel filters are an important part of the fuel system, but they can also be restrictive. Murphy prefers the late-model filters (bottom) used on fuel-injected engines. The fittings on both sides offer a more reliable connection, he says, and they can adequately feed up to 400 hp.
Fuel filters are an important part of the fuel system, but they can also be restrictive. M