FUEL SYSTEMS CHECKUP
Tips from tank to filter.
A fuel-system problem might leave you stranded on the water, or cause a fire or explosion. Problems caused by poor fuel quality and ethanol-extended (E10 and now E15) fuels increase maintenance and service costs, and even cause engine failure for boaters. Utilize these six tenets to help prevent inconvenience and tragedy.
FUEL LINE
Replace fuel lines older than three years with EPA-compliant hose. Install new clamps. The innards of older fuel hoses are susceptible to alcohol deterioration.
They can collapse or fall apart, clogging the fuel system and starving the engine of fuel. Newer fuel lines use a tough inner liner, visible by looking into the end of the hose. It makes the hose stiffer and harder to work with, and it’s more expensive. When routing the hose, make bends with a radius of at least 6 inches to prevent flow reduction.
FILTER
The fuel filter should be replaced at least annually. If your rig doesn’t have a water-separating fuel filter, now’s a good time to add one. Check the filter’s flow rate against your engine’s maximum fuel-burn rate. A filter with a drain bowl is superior. However, the standard spin-on types also work. Placement in the fuel line should be between the tank outlet and the engine inlet.
PRIMER BULB
Many outboards use primer bulbs, which may be damaged by ethanol fuels. A primer bulb should feel stiff and refill quickly after squeezing. Primer bulbs have check valves inside that can fail and leave you stranded. Use a factory primer bulb; aftermarket models are typically of lesser quality and won’t flow fuel as well as OEM units.
CLAMPS
Fuel-line clamps are critical. They prevent fuel leaks and, just as important, air leaks. Air leaks can ruin an engine in no time because the fuelair mixture will become lean and starve the engine for fuel. Use new clamps if the old ones won’t hold, are corroded or are falling apart. Hose clamps are cheap compared with a damaged engine. Many engine manufacturers use Oetiker (oetiker.com) clamps for fuel-hose connections. These are secure, high-quality clamps; however, they are single-use only, and can be difficult to remove and install without the proper tools. See your local marine-supply store.
TANK
Check the tank carefully for leaks, cracks and loose mounting. Unless it’s leaking fuel into the bilge, you might not even notice it. I’ve serviced fuel tanks that had all mounting tabs broken or cracked; the only thing keeping the tank in place was the weight of the fuel and tank-hose connections. While a new tank can be expensive, it’s still a lot cheaper than a boat fire.
ANTI-SIPHON VALVE
These are installed in the outlet fitting from the tank to the engine, usually threaded into the fitting, with a hose nipple on the other end where the fuel line connects. They keep fuel from flowing into the bilge if a fuel-line failure occurs. If you experience valve failure, don’t simply remove the check-valve ball and spring from inside the anti-siphon fitting. It’s against Coast Guard regulations and could get you in trouble insurance-wise, and might cause a fuel-related boat fire. Instead, replace it with a quality anti-siphon valve. Hint: Highquality valves cost three times as much as the cheap ones.