AquaCraft V24 One-Design - Manual (Page 8)

IDLE ADJUSTMENT:
Important: Do not confuse the idle screw with the low-speed
needle “L”. The idle screw physically adjusts how much the
carburetor valve can close. The low-speed needle “L” adjusts
the gasoline to air mixture when the engine is running at low
RPM. If your engine appears to work correctly except that the
low RPM are not as low as you want them to be, then adjust
the idle screw. If your engine behaves erratically at low RPM,
then adjust the low-speed needle “L”. When adjusting, turn
the screw about 1/8 of a turn each time. A dirty plug will make
it difficult to adjust the idle RPM. Follow the recommended
procedures if any of the following happens:
Problem:
• The engine hesitates when accelerated rapidly.
• The RPM increases at idling.
• The engine stops when the throttle is moved from high to low.
Solution: Your low-speed needle “L” is too lean. Open it up
about 1/8 of a turn and try again.
Problem:
• The idle is not steady.
Solution: Your low-speed needle “L” valve is too rich. Close
it 1/8 of a turn and try again.
HIGH-SPEED ADJUSTMENT:
The high-speed RPM and transition performance is adjusted
with the high-speed “H” needle valve. When adjusting, turn
the screw about 1/8 of a turn each time. The position of the
“H” needle will vary according to temperature and elevation.
If your engine is running smoothly then do not adjust this
needle valve. Follow the recommended procedures if any of
the following happens:
Problem:
• Engine stops at full throttle.
• Engine hesitates when accelerated rapidly.
• The engine will not come up to full RPM at full throttle.
Solution: Your high-speed needle valve “H” is too lean.
Open it up 1/8 of a turn and try again.
Problem:
• Your engine does not reach full RPM.
• Carbon build-ups appear consistently on your spark plug.
Solution: Your high-speed needle valve “H” is too rich.
Close it up 1/8 turn and try again.
To ensure long life and good performance from your Fuji BT-
24 Marine engine, you MUST break it in properly. To break-
in your BT-24 Marine, you need to run the engine for about
an hour with a fuel mixture that has a 25:1 (4% oil) fuel/oil
ratio. Patience is important here; the boat will run slowly
during the break-in process and the engine’s output power
will increase gradually over the first few tanks. Once the
engine is broken in and you begin running a 40:1 fuel/oil
mix, power will increase substantially.
• Do not adjust the high-speed needle on the carburetor to
break in the engine. If you do so, carbon will accumulate
in the spark plug and that will make ignition difficult.
• Do not run at full power for extended periods of time while
breaking in your engine.
• Make sure that the engine has adequate cooling.
Adjustments should be made on dry land with the boat
securely held in place.
BREAKING IN THE ENGINE
8