GASOLINE ENGINE 8.1 S INBOARD MODELS
Page 16 of 58
Fuel Delivery System
WARNING
Boating standards (NMMA, ABYC, etc.) and Coast Guard regulations must be
adhered to when installing fuel delivery system.
The main concern of a boat’s fuel system is safety; this must be achieved through a
technically sound installation and constant inspection.
The fuel system, from the filler pipe to the fuel pump is the same, in principle, for all boats.
The fuel tank is an integrated component of the boat. Refer to the special information on
service and maintenance, which you have received from the tank manufacturer.
Only a few points related to function and safety are listed here [Refer to boating standards
(NMMA, ABYC) and Coast Guard regulations for complete guidelines]:
•
All connections should be on the upper side of the tank.
•
The drain plug at the lowest point on the tank serves to permit the removal of water and
sediment.
•
The tank breather pipe must have an inner diameter of at least 1/2 in. (13 mm) and must
be fitted with a swan neck to prevent water from entering the tank.
It is recommended that the exact route and length of the fuel lines be established at the first
installation of the engine to prevent problems later in connecting them to the engine.
All fuel lines must be well secured. The holes where the lines run through the bulkheads
should be carefully rounded off, or protected with rubber grommets. This prevents damage
to the lines from abrasion.
The following, but not limited to the following, additional fuel connection related points, must
be considered [Refer to boating standards (NMMA, ABYC) and Coast Guard regulations for
complete guidelines]:
1. Fuel tank should be mounted below carburetor level (if possible) or gravity feed may
cause carburetor fuel inlet needle to unseat, and flooding may result.
2. The maximum measured vacuum at the engine’s fuel inlet must not exceed 2 in. Hg (6.9
kPa) at 650, 3000, full throttle rpm and back at idle rpm.
IMPORTANT: Vacuum reading higher than specified can cause vapor locking with
some of today’s fuels. It can also cause poor engine performance because of fuel
starvation.
3. Fuel pickup should be at least 1 in. (25 mm) from the bottom of fuel tank, to prevent
picking up impurities.
4. Fuel lines used must be Coast Guard approved (USCG Type A1).
