Exhaust System; Air Filter - LRP ZR.28 SPEC.4 PULLSTART Guia De Inicio Rapido

USER GUIDE
ZR.28 SPEC.4 PULLSTART
ORDER NO. 32803
Dear customer,
thank you for your trust in this LRP product. By purchasing a LRP nitro engine, you
have chosen a high-performance and highly sophisticated product, which doesn´t
make any compromise between maximum performance and easy tuneability. We hope
you enjoy your new engine.
Please read the following instructions carefully before you start using your LRP ZR.28
Spec.4 Pullstart engine. This user guide contains important notes for the installation,
the safety, the use and the maintenance of this product. Thus protecting yourself and
avoid damages of the product.
Proceed according to the user guide in order to understand your LRP ZR.28 Spec.4
Pullstart engine better. Please take your time as you will have much more joy with your
product if you know it exactly.
This user manual shall be kept in a safe place. If another customer is using this pro-
duct, this manual has to be handed out together with it.
1. Specification
Engine size
Bore
Stroke
Number of ports
Main bearing
Crankshaft 14.0mm / 10.0mm bore / SG shaft / Triple Turbo scoop
Crankcase Black XTEC T6 .28 Heavy-Duty Competition
Piston Specially lightened, high-silicium alloy
Connecting rod Knife-edge shaped, extra strong Aluminium
Glow Plug Standard style, LRP Standard R5 (No. 35051) included
XTEC PowerCarb3 15S-2 with 9mm venturi.
Carburetor
Power output*
Max. RPM*
Weight
Suitable for 1/8th Offroad Buggies and Truggies
*figures may vary depending on used fuel, muffler and tuning.
2. Fuel
Never use regular gasoline or airplane fuel. Use fresh 2-stroke model car fuel only!
We recommend using our line of LRP Energy Power fuels (No. 35712: 25% 1L / No.
35732: 25% 3,5L). For the LRP ZR.28 Spec.4 Pullstart engine, we recommend a fuel
with 25% nitro. Never exceed 36% nitro. A higher nitro content will decrease your
engine's lifetime.
3. Airfilter
A good airfilter is very important for the life of your engine. Never run without an airfil-
ter, as quick and permanent damage will result! Don't forget to impregnate the airfilter
with a suitable oil before usage. Carefully clean the airfilter at least after every tenth
tank. Replace the airfilter every 3 litres (~1 gallon) of usage.
We recommend the use of our LRP Hi-Flow 2-Stage oval airfilter (No. 36565) together
with our LRP Hi-Flow airfilter oil (No. 36590).
4. Glowplug
Use only standard style glowplugs for this engine. We recommend using our line of
high-quality LRP Platinum / Iridium glowplugs (No. 35031 - No. 35061, 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. If the glowplugs wear out too fast, an
MA00267 © LRP electronic GmbH 2016
.28 (4.57 ccm)
18.50mm
17.00mm
6 + 1 (6 x transfer, 1 x exhaust)
Precision ball bearing
Made from lightweight Aluminium.
3.93 HP
33.900 RPM
420g
3.93 HP
33.900 RPM
ENGLISH
additional 0.1mm shim between burnroom and liner is recommended. Whenever you
have trouble with the engine stalling for no reason, replace the glow-plug first!
TIP: Our LRP team always uses a LRP Platinum / Iridium R5 (No. 35051) plug for the
LRP ZR.28 Spec.2 Pullstart engine.

5. Exhaust system

Never run without a pipe since this will cause excessive overheating and may damage
your engine. A good pipe has a very huge effect on the performance of a 2-stroke en-
gine. For the LRP ZR.28 Spec.4 Pullstart engine, we recommend using our high-quality
LRP Screamer-93 1/8 Off-Road Exhaust System (No. 36255) for maximum performan-
ce.
6. Carburetor
The factory settings of the engine are as following and are a good starting point for
you, if you are not satisfied with your carburetor settings. Turn in the needles com-
pletely (Caution: Do not overtighten them!) and loosen them the required number of
turns again:
1. Factory setting
• Main speed needle: 5 turns
• Mid range needle: 3 1/2 turns
2. Basic setting after run-in
• Main speed needle: 4 1/4 turns
• Mid range needle: 3 1/4 turns
Idle screw (#1):
Adjusts the air flow when carburetor is ful-
ly closed. Turn CW for higher idle-speed
and CCW for lower idle-speed. Should be
open approx. 0.5mm.
Mid range needle (#2):
Adjusts the mid/low-speed flow rate of the
fuel. Turn CW for leaner and CCW for richer
setting.
Main speed needle (#3):
Adjusts the main flow rate of the fuel (when the throttle is opened significantly). Turn
CW for leaner and CCW for richer setting.
7. 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.
8. 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:
LRP electronic GmbH
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73614 Schorndorf
Deutschland
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