Turmoil Pro •
www.sportwerksRC.com
Starting Your Engine for the First Time
Break In
The first start-up and the first few minutes your engine is running is the most
critical time of its life and, in many ways, dictates how well it will perform
and how long it will last.
During the first runs, when the engine starts, the exhaust should emit
blue/white smoke, indicating the engine is rich (a good thing during break
in). During the first tank of fuel, you may want to set a higher than normal
idle speed in order to keep the engine from stalling. Drive your buggy while
“blipping” the throttle and avoid operating the engine at full throttle for
more than 2–3 seconds at a time. Run the entire first two tanks of fuel in
this manner. After the first two tanks of fuel, begin leaning out the high-
speed needle valve 1/8 turn at a time. It generally takes about 5 or 6 tanks
of fuel before you’d want to start tuning for “maximum” power. Patience
during break in will be rewarded with an engine that performs reliably and
at its maximum power potential. Remember, glow plug failure is a common
occurrence when breaking in a new engine. To test your plug, let the engine
idle for a short period. Attach the glow igniter to the glow plug. Then, remove
the igniter. If you hear no appreciable change in the engine rpm, the plug is
still good. If the engine loads up and the rpm's decrease, it’s time to replace
the glow plug.
Tuning Your Engine
When tuning the needle valves for maximum performance, adjust them in
small increments, 1/16 turn at a time. An engine should not be run too lean;
doing so severely shortens the life of the engine. When an engine is set too
lean, it will run very strong at first but will soon begin to sag and hesitate
or stall when accelerating. The best way to tune an engine is by using an
infrared temperature gauge, but you can also use water to check the head
temperature. (Refer to “Fine Tuning Your Engine”)
Fine-Tuning Your Engine
As you gain experience, you’ll be able to tune your engine based on the
engine’s sound and feel during acceleration and at full throttle. Until you
have developed this skill, we recommend the following method of engine
tuning. Start your engine and drive your buggy aggressively for about two
minutes. Place a drop of water on the cylinder head. If the water sizzles away
(evaporates immediately), the needle setting is too lean. A correct needle
setting will result in the water evaporating slowly, in about 5–10 seconds. If
the water does not evaporate, the needle setting is too rich. Lean the high-
speed needle 1/8 of a turn and run the engine again, adjusting the needle
setting to get the desired evaporation rate of 5–10 seconds. Check the
temperature each time you change the needle mixture. Do not let the engine
overheat, as this will damage the engine!
Tuning the Low-Speed Needle
The low-speed needle (also referred to as the idle mixture or idle needle)
should be set after you’re satisfied with the high-speed needle setting. After
achieving the engine’s proper operating temperature, reduce the engine
throttle to idle for about 15 seconds. Now pinch the fuel line with your
fingers, close to the carb fuel inlet nipple when carefully listing the engine
rpm. If the engine dies immediately without an increase in rpm, the low
speed needle is set too lean.
If the rpm’s increase dramatically and then the engine dies, the setting is too
rich. The idle setting results in the rpm’s increasing a slight amount (about
200 rpm’s) after pinching the fuel line before dying.
Setting the Idle RPM
The last setting to be made is the idle rpm. Tuning the idle stop
screw clockwise increases the idle speed; whereas turning the screw
counterclockwise will make the engine idle at a lower rpm. Ideally, the engine
should idle just fast enough to give a reliable idle but not engage the clutch
and, of course, never flame out.
