Troubleshooting Guide - LRP ZR.28 SPEC.4 PULLSTART Guia De Inicio Rapido

USER GUIDE
ZR.28 SPEC.4 PULLSTART
ORDER NO. 32803
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.
9. 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 the engine over several times so the oil spreads evenly
inside the engine.
10. 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
MA00267 © LRP electronic GmbH 2016
3.93 HP
33.900 RPM
ENGLISH
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!
11. Trouble shooting guide
PROBLEM REASON
Glow plug defective
Glow plug does not work
properly
Engine is set too rich (too
Engine does not
much fuel, hits back)
start
Engine is too lean (too little
fuel, does not start)
Engine doesn't suck in the
fuel
Glow plug defective
Bad fuel
Bad carburetor setting
Engine stops
after a short
time after glow
plug igniter has
Dirt in fuel line or carburetor
been discon-
nected
Fuel line damaged
Loose glow plug or
cooling head
Air filter old or dirty
Engine is set too lean
Performance
decreases after
Glow plug defective or
reaching opera-
wrong type
ting temperature
or engine stalls
from time to Engine runs too hot
time
Shims under comb. chamber
wrong
Bad carburetor setting
Engine still
keeps running
at high RPM for
a moment when Glow plug, wrong type
you release the (too hot)
throttle
Shims under combustion
chamber wrong
LRP electronic GmbH
Hanfwiesenstraße 15
73614 Schorndorf
Deutschland
SOLUTION
- replace glow plug
- check the condition of the
glow plug
- check the glow plug igniter
- check carburetor settings,
repeat tuning procedure
- unscrew the glow plug
completely and use startbox
for 5sec
- check carburetor setting,
repeat tuning procedure
- check the fuel line for
possible damage
- check the carburetor setting
- replace glow plug
- replace fuel by fresh and
correct type of fuel
- check the carburetor
setting, repeat tuning
procedure
- clean fuel line, clean &
check carburetor
- replace fuel line
- tighten glow plug and/or
cooling head
- clean or replace air filter
- check the carburetor
setting, repeat tuning
procedure
- replace the glow plug by a
correct type
- run-in process is not
completed
- check number of shims
- open mid-range needle
¼ turn at a time and
re-adjust idle-speed
- set idle speed lower
- use glow plug with higher
number (e.g. go from 5 to 6)
- check number of shims