Page 14 - Arrow Shark 2020 RC Boats

The Engine Operation Guide

Starting The Engine

Before starting your engine, make sure that it is securely mounted in your boat with appropriate fuel and
exhaust systems. Read through all the following instructions before starting. If your radio is installed
and your throttle servo linked to the engine, ensure that the carburetor controls operate as explained in
the “Carb Settings” section. If the engine is connected to your flex shaft drive and propeller, check that
they are properly aligned and that due care is taken to keep everything well clear of the prop. Remember
that the prop is very sharp, and also that the engine and exhaust will get quite hot when running. Do not
run the engine for more than a minute without a supply of cooling water, and never run the engine at
more than low revs with the boat out of the water.

The 2020 RC boat's package comes with an M-39X Pro-Mod barrel type racing carburetor which does
not have a primer bulb, choke or return gas line like the more common WT644 or WT711 carbies that
are usually fitted to stock Zenoah or CY engines. The M-39 carb gives ultimate performance but does
require a different starting procedure. Having prepared your engine and boat in the usual way (with full
regard to all safety aspects), and having filled your fuel tank, follow these steps for easy starting:

Manually choke the engine by blocking the carb intake venturi with your thumb or finger and slowly
pull the starter rope a few times. The M-39X venturi is much larger than other carbies, so you may need
to wear a glove for your thumb or finger to fully seal the venturi for effective choking of the engine.

Check that fuel is being sucked along the gas line up to the carb; continue slowly pulling the starter rope
until the gas line is clear or bubbles and you can feel fuel wetting your thumb or finger.
Remove your thumb or finger from the carb and open the throttle a bit less than half way.
Slowly pull the starter rope one more time to check the engine is not flooded (see below).
Smartly pull the starter rope in the usual way until the engine starts.
Bring the throttle back to a steady idle ­ DO NOT allow the engine to over­rev as this can cause
damage.

If too much fuel is sucked into the engine as you choke it, the engine will be flooded and will not start.
It may be harder to pull over on the starter as the excess fuel increases compression. If this happens:

1.Remove the spark plug and carefully wipe dry the electrodes with a clean rag before setting the plug
safely aside.
2.Hold the clean rag just above the plug hole and pull the starter rope smartly a few times to clear the
excess fuel.
3.Re­install the spark plug and open the throttle a big less than half way.
4.Slowly pull the starter rope to check that compression is back to normal.
5.Smartly pull the starter rope in the usual way until the engine starts.
6.Bring the throttle back to a steady idle.

For “hot re­starts” you may not need to choke the engine. Check that the fuel line is full of gas without
any bubbles and smartly pull the starter rope. If the engine doesn’t start after a few pulls, then manually
choke the engine as above and slowly pull the starter rope until you can feel fuel wetting your thumb or
finger before removing it from the carb venturi. Slowly pull the starter one more time to check the
engine is clear, and then pull smartly until the engine starts.

To start the X-60 Marine engine, we recommend to start one cylinder first, leave the other cylinder
without spark plug installed in order to reduce the compression for easier starting with pull starter. when
the first cylinder starts, keep it running for 20 seconds at idle speed, then, stop it, and install the spark
plug into the other cylinder, and now, you can easily to start both cylinders at same time.

14