MJM Yachts 34z Express - Manual (Page 13)

CHAPTER 3 PROPULSION SYSTEM
- 13 - 34z
3.9 STOPPING
Before shutting down the engine, allow it to cool down by idling in neutral for 5 minutes. Then,
press and hold the red button on the engine panel until the engine comes to a complete stop.
Make sure to turn the key to the OFF position after the engine stops so that the engine hour
meter stops. Note that if the key is switched OFF before the red button is pushed, the button will
not shut-down the engine.
3.10 RUNNING
The Yanmar 6LY2A is rated at a maximum RPM of 3400. Running the engine at full throttle is not
recommended for extended periods of time. Yanmar claims that the engine can be run “all day” at
200 RPM under the max RPM. At 2800 RPM, you should be cruising at 24-26 knots, depending
on load, wind, etc. It’s whatever seems comfortable considering conditions. While running, pay
attention to the instrument gauges on the dash console. A significant change in temperature, oil
pressure, or voltage should be investigated immediately, before the engine is damaged.
3.11 THROTTLE
CONTROL
The single-lever control to the starboard side of the console governs both the throttle and shifting
functions. It is important to allow the transmission to engage into forward (or reverse) before
throttling up. The boat utilizes a powerful propeller with a large rudder immediately behind. It is
uncommon in docking situations to ever need more than a short, momentary forward or reverse
thrust.
Crabbing Sideways: Since there is more directional response with the helm hard over in forward
than in reverse, due to the prop wash bouncing off the rudder, it is possible in combination with
the bow-thruster to crab the boat sideways for an eggshell landing. For example, to move the
boat sideways to starboard from a dead stop: Turn the wheel fully to port. Give the throttle a
short burst FWD for 1-2 seconds. The stern is pushed to starboard. To keep the boat parallel
with the dock, or another boat you are rafting up to, tap the bowthruster to STBD. If the boat
starts sliding forward, give it a touch of reverse to hold station. Repeat process above several
times. This is a skill that is best practiced in open water before attempting docking maneuvers.
To increase RPMs in neutral, you must have the lever in the neutral position and then pull the
handle outboard, then advance it forward while it is out of gear.
3.12 INSTRUMENT
GAUGES
The engine instrument gauges provide you data on the status of the engine. They are powered
via the ignition switch and will not display data when the key is in the OFF position. The
tachometer allows you to monitor the RPM of the engine. It is common and efficient to cruise at
85% of the rated maximum RPM, or 2800 RPM. For acceptable ranges of temperatures and oil
pressures shown in other gauges, consult the engine’s operator’s manual.