LRP electronic ZZ.21C CERAMIC SQUARE STROKE Manual De Instrucciones página 5

USER GUIDE
ZZ.21C CERAMIC SQUARE STROKE
BEST.-NR. 32123
8. Run-in
Proper run-in of the engine is a very important step in ensuring that you get the highest
performance and lifetime of your engine. Take your time for proper run-in. Do not use
run-in benches, but use your car for run-in. Use the same fuel as you will be using for
the life of the engine. Special run-in fuel is not needed. If your engine doesn't start
easily you may try loosen the glowplug by ½-turn to decompress the engine and try
again. Don't forget to tighten the glow-plug again once the engine started!
Procedure:
• Start the engine and set the main-needle very rich, i.e. excessive smoke coming
from the muffler. The factory settings are a good starting point.
• Let the engine idle for 2mins first to warm it up. You probably have to raise the idle
with the idle screw so your engine does not cut off.
• Now start driving your car for 8 full tanks, it will be slow and sluggish, but this is an
important step.
• ATTENTION: Do not run the car until the tank is completely empty so that your en-
gine will cut off due to not enough fuel. Do not allow the engine to rev-up too high,
run the engine at half speed on the straightaway.
• The engine should not be too cold and not too hot during run-in, 70-90°C (160-200°F)
is perfect.
• Let the engine cool down completely after this run-in procedure.
9. Tuning
It never hurts to have the mixture too rich, but NEVER let the mixture get too lean.
Always tune from rich to lean. If in doubt, richen it up first! Never try to tune a cold
engine, run 2-3 minutes to get the engine up to running temperature before doing
any adjustments!
Basic tuning procedure is as follows:
1. Set the engine's idle speed up slightly higher than normal.
2. Start tuning your engine with the settings too rich.
3. Always tune main-speed needle (top-end) first.
4. Tune mid-range needle next.
5. Reset idle speed screw.
Procedure:
1. Set the idle speed so your engine doesn't stall (slightly higher then normal).
2. Go to the track with the main-needle set too rich, there should be heavy smoke
coming from the muffler now.
3. Tune the engine by leaning the main-needle 1/8 turn at a time (turn clockwise).
- Your goal will be that the engine will just reach maximum RPM on the straighta-
way.
- Open the main-needle again by an 1/8 turn (turn counter-clockwise) when you
have reached that point. This should be the perfect setting for the main-needle.
Temperature of 95-105°C (200-225°F).
- If the main-needle is set too lean, the engine will overheat and will not acce-
lerate smoothly. If this happens, immediately stop the engine and richen the
main-needle (counterclockwise) 1/4 turn before a new attempt.
4. Adjust the mid-range needle now. Run 3 full laps, stop the car near you and let it
idle for 5secs. „Push off". It should have slightly richened up (idle rpm gets lower),
but still accelerate quickly. If it died before the 5secs, check the following:
- If the rpm constantly decreases and finally the engine stops, the mid-range
needle is too rich.
- If the idle-speed increases during idle, the mid-range needle is too lean.
5. You may have to re-adjust the idle-speed now. If it idles too high, the clutch may
not release completely and you will lose „snap" off the corners. If it idles too low,
it may stall at the start, or at the end of the straightaway when you release the
throttle.
Ways to measure the engine temperature:
• Temperature gauge method (recommended): Pull in quickly and immediately take
a temperature reading. Place the gauge directly over the engine pointed at the
glow plug.
• Spit method: Pull in quickly and immediately put some spit on the engine's head.
The spittle should just slowly boil off (2-3secs). It should not dance around as if it
were on a hot griddle, nor should it lay there and steam.
MA00270 © LRP electronic GmbH 2017
2.99 PS
40.500 RPM
ENGLISH
10. After run
Use after-run oil to keep everything lubricated after you have finished your day.
After-run oil helps for an easy start the next time and protects your internals against
rust. Use only „after-run oil" specially formulated for R/C engines. Do not use silicone
shock oil or similar as they will seriously harm your engine. We recommend to use
our LRP After-Run oil (No. 37910), which you should use regularly after using your
engine.
Procedure:
First let the tank run completely empty at idle until it runs out of fuel (try re-starting it
several times), next put a few drops down the open carburetor and a few drops down
the glow plug hole. Spin it over for 5 seconds on the starter box and you are done.
11. Maintenance
Treat your engine with care and check it frequently. Due to the extremely high RPM
this engine produces, any fault can cause serious damage. All moving parts inside the
engine are subject to wear, you must know if a piston/liner/conrod has worn out and
if they need to be replaced. If you replace one part, please check if everything else is
still in good shape at the same time. If you only change one part and other parts are
in bad shape, there's the possibility that there will be a new failure soon!
Some important matters:
• Clean the outside of the engine properly before you open it. Any dust or dirt which
gets into the engine could make considerable damage.
• Check the conrod frequently. If you want to replace the conrod, be sure the big end
of your crankshaft is still round and at a good size. If not, also replace the cranks-
haft.
• When you start putting your engine back together, make sure that each part is
totally clean before installation and please use some oil (after-run is suited well) to
lubricate everything.
• Be careful that each part has its correct direction, especially piston/liner/conrod.
Please also check the explosion drawing. The lubrication hole in the conrod should
be facing to the front (direction to the carburetor).
• Before you install the combustion chamber, please doublecheck that you installed
all head shims.
• Use a hex wrench to install the screws. When you start to feel resistance, stop
turning the screw. Repeat this for each screw, use the star-technique to tighten all
the screws completely. Do not overtighten them!
LRP electronic GmbH
Hanfwiesenstraße 15
73614 Schorndorf
Deutschland
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