LRP Z.18S Pro Pullstart User manual

Instruction Manual Z.18S Pro Pullstart #31800
Please read and understand these instructions completely before you install your engine.
TECHNICAL DATA:
*Figures may vary depending on used fuel, muffler and tuning.
WARNING NOTES:
?? Never leave your RC model unattended when the engine is running. If a fault should occur the result could be a
fire in the model which could destroy anything else in the v cinity.
?? Nitro engines produce gases wh ch are very dangerous for your health; one of them is carbonium monoxide which
can lead to death! Always use your engine outdoors or in well ventilated areas.
?? Running nitro engines and it’s surroundings get very hot, you can ser ously burn yourself when you touch t w th
your fingers.
?? Never try to stop a running engine with your fingers. Please interrupt/pinch the fuel line, or close the top of the
carburetor.
?? Not suitable for children under 14 years, this engine is not a toy.
FUEL:
Use fresh 2-stroke model car fuel only, never use regular gasoline or airplane fuel! We recommend using our line of
LRP high-qual ty fuels. For the LRP Z.18S Pro Pullstart engine we recommend fuel with 16% n tro. A higher n tro
content decreases your engine’s lifetime. Do never exceed 30%.
AIRFILTER:
A good airfilter is very important for the life of your engine. Never run w thout an airfilter, as quick and permanent
damage will result! Don’t forget to impregnate the airfilter w th a su table oil before usage. Carefully clean the airfilter
at least after every fifth tank. Replace the airfilter every 3l tres (~1 gallon) of usage.
GLOW-PLUG:
Use only standard style glow-plugs for this engine, we recommend using our line of LRP high-quality glow-plugs
(availabe as R3 to R6). Check them frequently and never run with worn-out or old glow-plugs since they could damage
your engine. They turn dull when your engine was too lean and should be replaced, they should stay bright like
chrome. Whenever you have trouble with the engine stalling for no reason, replace the glow-plug first!
EXHAUST SYSTEM:
Never run w thout a pipe since this will cause excessive overheating and may damage your engine. A proper pipe lets
2-stroke engines run properly and fast. We recommend using our line of LRP high-qual ty pipes and headers.
PULL STARTER:
Always pull the handle straight and don’t let the cord rub on anything. Do not fully extent the cord as this may abuse
and damage the pull starter (using about 2/3 of the complete length of the cord is enough to start your engine).
Don’t let fuel get in contact with the pull starter as this may weaken t. The Pull Starter is designed to start the engine
running in a counterclockwise rotat on. Forcing the flywheel clockwise will cause sever damage to the pull
starter.
Engine Size .18 (2.95ccm)
Exhaust Side
Bore 15.9mm
Stroke 14.7mm
Liner ABC
Number of ports 3+1 (3x transfer-1x exhaust-port)
Crankshaft Standard Shaft
Crankcase LRP .18, black anodised
Piston Fully CNC-machined high-silicium alloy
Connecting Rod Fork shaped aluminium using double bushings
Glowplug Standard style, LRP Standard R3 (No. 35030) included
Carburetor Rotary carburetor 6mm venturi aluminium design
Power Output* 1.51 PS
Useable RPM range* 3.000 –31.000
Weight 270g

CARBURETOR:
The factory settings of the engine are as following and are a good starting point for you. Turn in the needles completely
(Caution: do not overtighten them!) and loosen them the required number of turns again:
?? Mid range: 3,5 turns
?? Main: 4 turns
Idle screw (No.1): Adjusts the air flow when
carburetor is fully closed. Turn CW for higher idle-
speed and CCW for lower idle-speed. Should be
open 0.5-1.0mm.
Mid range needle (No.2): Adjusts the mid/low-
speed flow rate of the fuel. Turn CW for leaner
and CCW for richer setting.
Main speed needle (No.3): Adjusts the main
flow rate of the fuel (when the throttle is opened
signif cantly). Turn CW for leaner and CCW for
richer setting.
RUN-IN:
This 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. We do not recommend using run-in benches, use your car for run-in and use the same fuel as
you will be using for the life of the engine. If your engine doesn’t start easily you may try loosen the glow-plug by ½-
turn to decompress the engine and try again, don’t forget to tighten the glow-plug again once it started!
Procedure:
?? Start the engine and set the main-needle very rich, i.e. excessive smoke coming from the muffler.
?? Let the engine idle for 2mins first to warm it up.
?? Now start driving your car, t will be slow and sluggish, but this is an important step.
?? 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 (160-195°F) is perfect.
?? Let the engine cool down for 15mins after each tank during the run-in per od.
?? We recommend doing so for 4 tanks of fuel before you start tuning your engine.
TUNING:
It never hurts to have the mixture too r ch, but NEVER let the mixture get too lean. Always tune from rich to lean. If in
doubt, r chen it up first! Never try to tune a cold engine, run 5 full laps 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 m d-range needle next.
5.Reset dle speed screw.
Procedure:
1.Set the dle speed so your engine doesn’t stall (slightly higher then normal).
2.Go to the track w th 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.
?Your goal will be that the engine will just reach maximum RPM on the straightaway.
?Open the main-needle again by an 1/8 turn when you have reached that point, this should be the perfect
setting for the main-needle (temperature of 95-110°C / 200-230°F).
?If the main-needle is set too lean, the engine will overheat and will not accelerate 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 dle for 5secs. "Push off"...
It should have slightly richened up, but still accelerate qu ckly. If it died before the 5secs, check the following:
?If t seemed to load up and slowly stop, the mid-range needle is too rich.
?If the dle-speed increased before t stopped, 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, t may stall at the start, or at the end of the straightaway when
you release the throttle.
Ways to measure the engines temperature:
?? Temperature gauge method (recommended): Pull in qu ckly 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 sp t on the engine’s head. The saliva should just slowly
boil off (2-3secs). It should not dance around as if t were on a hot griddle, nor should t lay there and steam.
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2
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AFTER RUN:
Use after-run oil to keep everything lubr cated 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 sil cone shock oil or similar as they will seriously harm your engine.
Procedure:
First let the tank run completely empty at dle until it runs out of fuel (try re-starting t several times), next put a few
drops down the open carburetor and a few drops down the glow plug hole. Pull the pullstarters chord 5-times and you
are done.
MAINTENANCE:
Treat your engine w th care and check t frequently. This engine will rev up to 30'000 RPM and any fault at such high
RPM can cause ser ous 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 outs de 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 crankshaft.
?? When you start putting your engine back together, make sure that each part is totally clean before installat on and
please use some oil (after-run is su ted well) to lubricate everything.
?? Be careful that each part has its correct direction, especially piston/liner/conrod. Both the lower part of the piston
and the lubr cation hole in the conrod should be facing to the front (direct on to the carburetor).
?? Before you install the combust on 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!
TROUBLE SHOOTING GUIDE:
PROBLEM REASON SOLUTION
Glow plug defective ?replace glow plug
Glow plug does not work properly ?check the condition of the glow plug
?check the glow plug igniter
Engine is set too rich
(too much fuel hits back)
?check carburetor settings, repeat tuning procedure
?unscrew the glow plug completely and use startbox for 5sec
Engine is too lean
(too little fuel, does not start)
?check carburetor setting, repeat tuning procedure
Engine does not start
Engine doesn’t suck in the fuel ?check the fuel line for possible damage
?check the carburetor setting
Glow plug defective ?replace glow plug
Bad fuel ?replace fuel by fresh and correct type of fuel
Bad carburetor setting ?check the carburetor setting repeat tuning procedure
Dirt in fuel line or carburetor ?clean fuel line, clean & check carburetor
Fuel line damaged ?replace fuel line
Loose glow plug or cooling head ?tighten glow plug and/or cooling head
Air filter old or dirty ?clean or replace air filter
Engine stops after a short time
after glow plug igniter has
been disconnected
Engine is set too lean ?check the carburetor setting, repeat tuning procedure
Glow plug defective or wrong type ?replace the glow plug by a correct type
Engine runs too hot ?run-in process is not completed
Performance decreases after
reaching operating
temperature or engine stalls
from time to time Shims under comb. chamber wrong ?check number of shims
Bad carburetor setting ?open mid-range needle ¼ turn at a time and re-adjust idle-speed
?set idle speed lower
Glow plug, wrong type (too hot) ?use glow plug with higher number (e.g. go from 6 to 7)
Engine’s still keeps running at
high RPM for a moment when
you release the throttle Shims under comb. chamber wrong ?check number of shims
Please always check www.lrp-electronic.de for guidance if you are experiencing problems!