RENNTECH AIXRO XR50 User manual
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
INTRODUCTION!!!!!!TECHNICAL SPECIFICATIONS
1.1!preface!!!!1! ! 7.1!data!!!!13
1.2!state of development! ! 1! ! 7.2!torque specs!!!13
1.3!target readers!!!1! ! 7.3!fuels!!!!13
1.4!copyright info.!!!1! ! 7.4!carburetor !!!13
! !!!!!!7.5!ignition and spark! ! 14
PRODUCT DESCRIPTION!!!!!7.6!clutch!!!!14
2.1!functions of the rotary engine!2! ! 7.7!starter !!!!14
2.2!area of application! ! 3! ! 7.8!fuel pump!!!14
2.3!identifying components! ! 3
! !!!!!!TIPS AND TRICKS
ASSEMBLY PROCEDURES!!!!!8.1!RENNtech faq!!!15
3.1!cooling system!!!4
3.2!engine assembly!!!4
3.3!chain tensioning!!!6
3.4!fuel and fuel lines! ! 6
3.5!electrical connections! ! 7
3.6!exhaust manifold! ! 7
3.7!exhaust pipe!!!7
3.8!starter !!!!8
INITIAL OPERATION
4.1!check-up!!!9
4.2!starting the engine! ! 9
4.3!test run!!!!10
4.4!after the test run! ! 10
OPERATION
5.1!warm-up and break-in! ! 11
5.2!driving!!!!11
5.3!switching off!!!11
MAINTENANCE AND WARRANTY
6.1!wear and tear items! ! 12
6.2!issue of warranty! ! 12
6.3!warranty procedures! ! 12
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
CONTENTS
1
INTRODUCTION
1.1
PREFACE
RENNtech would like to thank you for your purchase of a new Aixro XR50 rotary powersports engine. By
doing so, you have helped set new standards for performance and environmental responsibility.
Before you get started, it is imperative that you read and understand the instructions and procedures
outlined in this operator manual. Inside, you will find information to help you with the initial setup and
maintenance of your Aixro, as well as prevent potential damage.
Again, thank we’d like to thank you - and wish you luck in all your adventures!
Sincerely,
Hartmut Feyhl
president, RENNtech INC.
1.2
STATE OF DEVELOPMENT
The procedures and instructions outlined in this manual represent the most current data available at the
time of publication. Some printed specifications may deviate from actual specs. due to advances in
production methods or design changes.
1.3
TARGET READERS
This operator manual is intended for anyone who intends to install, operate, or service the Aixro XR50
rotary engine.
1.4
COPYRIGHT INFO.
All rights reserved.
The circulation or duplication of this document, in part or in whole, is not permitted without the express
permission of RENNtech INC. and /or Aixro GmbH.
TITLE: RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
2
PRODUCT DESCRIPTION
2.1
FUNCTIONS OF THE ROTARY ENGINE
Aixro’s XR50 is a 4-cycle rotary piston engine based on the Felix Wankel patents. Like other
racing 2-cycle and 4-cycle rotaries, the XR50 is lubricated by a 40:1 fuel/oil mix.
The XR50’s rotor revolves around an eccentric crankshaft, which eliminates oscillating masses
to produce a unique, vibration-free experience. The rotor spins at 1/3 the rotational speed of
the eccentric shaft, igniting one of its three chambers each revolution.
Rotary engines offer many special advantages when compared to conventional piston engines.
These include vibration-free running (due to evenly balanced rotating masses), very compact
construction, outstanding power-to-weight ratios, outstanding low-rpm torque, and very low
emissions.
The primary components of the Aixro XR50 include:
•water-cooled casing (called a trochoid, due to the shape of its interior outline)
•rotor and gaskets (similar, in function, to conventional pistons and rings)
•eccentric shaft (similar to a conventional crankshaft)
•water-cooled side plates
The XR50 makes use of a carburetor to deliver a 40:1 fuel/oil mix (approx. 2% oil). Due to the
high operating temperatures of the rotary, the oil burns completely without the environmentally
harmful residues normally associated with 2-cycle engines.
At low rpm, fresh air and fuel (pre-mix) passes through a side plate before going through the
rotor and into the opposite side plate, cooling the rotor, bearings, and eccentric shaft. From
there, the air flows into the combustion chamber.
At approx. 5500 rpm, a vacuum-actuated valve opens, and the air/fuel mix is able to flow
directly through the periferal port and into the combustion chamber. This increases efficiency
at high rpm by allowing more oxygen into the chamber, which adds to the enormous
performance of the XR50.
These and other special processes (unique to rotary engine architecture) produce a fraction of
the harmful emissions of comparable 2-stroke engine, and are on par with some of the best
racing 4-strokes.
For even cleaner performance, the XR50’s high operating temperatures allow it to be fitted with
a catalytic converter.
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
3
PRODUCT DESCRIPTION
2.2
AREA OF APPLICATION
Aixro’s XR50 is designed exclusively for use in racing go-karts. Any use or development of the
XR50 for other applications is strictly prohibited, except with the express, written consent of
Aixro GmbH and/or RENNtech INC.
2.3
IDENTIFYING COMPONENTS
1. !trochoid
2. !eccentric shaft
3. !rotor, gaskets
4. !carburetor
5. !ignition module, spark coil, and spark plugs
6. !clutch
7. !starter
8. !vacuum-actuated valve
9. !throttle valve
10. !fuel pump
11. !side plate ignition side with static pinion and bearing
12. !side plate output w/ bearing
13. !exhaust manifold (aka “header”)
14. !exhaust pipe (aka “silencer”, or ”muffler”)
15. !water supply
16. !kill switch
17. !encasement
18. !engine mount
19. !engine support
20. !bell housing
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
4
ASSEMBLY PROCEDURES
3.1
COOLING SYSTEM
The XR50 is a liquid-cooled motor that uses an external water pump driven by the rear axle to
cycle water and coolant through the radiator. The radiator and cooling systems can be installed
on the left side of the kart without strain or stress on the chassis.
Water hoses should be free of any sharp bends or kinks, and run from the bottom connector on
the radiator to the central connector of the water pump (inlet). The hose should lead from the
pump outlet to the front engine connection. The engine’s water exit (next to the exhaust mani-
fold) takes up the hose leading back to the radiator. (see pg. 5)
The cooling system should be filled with a mix of water and coolant.
Routine checks should be made to ensure tightness*. Route the return hose in a sufficient dis-
tance from the exhaust pipe. Check that there are no sharp bends in the hose connections and
that the hoses do not touch any rotating parts.
Fasten all hose connections with hose clips while allowing suffecient movement
Should insert a water temp during this installation
!TIP: a small amount of antifreeze prevents corrosion.
!TIP: place water temperature sensor as close as possible to the exhaust port, or (ideal) directly
into engine housing.
3.2
ENGINE ASSEMBLY
Assemble the engine mount (torque to 26 Nm).
Remove the clutch cover.
!TIP: place the engine on the chassis and align the chain / sprockets.
ATTN: DO NOT DISABLE VACUUM SOLENOID
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
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RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
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ASSEMBLY PROCEDURES
(continued)
3.3
CHAIN TENSIONING
Generally, the engine should be mounted as close to the rear axle as possible to achieve the
shortest chain length (in this case, approx. 33”). Be sure to choose a suitable rear sprocket for
your racetrack, such that engine rpm does not exceed 10500 at your kart’s top speed on the
longest straights.
!TIP: if the gearing of a 100cc racing kart for your track is 10/82, subtract 37 from the large
chain ring - this will give some indication of the correct gearing (e.g., 82 – 37 = 45). Note that
this is merely a guide, and it is important to closely monitor engine RPM (while driving) to adjust
sprocket/gearing accordingly.
At the tightest spot on the chain, it should be possible to move chain (slack) approx. 10mm.
Once the chain is tensioned correctly, assemble the clutch cover.
!TIP: over-tightening the chain will damage the clutch and bearings.
!TIP: do not use a chain lock or master link - the chain must be riveted. RENNtech recommends
Regina O-ring chain (available from RENNtech for 89.00USD). Clean and lube chains regularly,
using O-ring safe cleaners (such as WD40). Stronger cleaners (brake cleaner, etc.) will dry out
and damage the O-rings.
3.4
FUELS AND FUEL LINES
The Aixro XR50 can be run using 91 octane “premium” unleaded without problems. RENNtech
recommends a 93 octane “premium” (determined with the formula: (MOZ+ROZ) / 2, where MOZ
is “motor octane”, and ROZ is “research octane”). Petrol-resistant rubber fuel lines should be
used at all times, and a fuel filter should be mounted between the fuel tank and the inlet to the
XR50’s fuel pump. The fuel line for connecting the fuel pump to the carburetor’s float chamber
is pre-assembled.
!TIP: the engine MUST BE RUN WITH A FUEL/OIL MIX, approx. mix ratio of 40:1.
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
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ASSEMBLY PROCEDURES
(continued)
!TIP: use only self-mixing, high-quality synthetic two-stroke racing oils with high flash-points
(Motul is recommended).
3.5
ELECTRICAL CONNECTIONS
The XR50 can be switched off using a red STOP button (included), which can be mounted on a
kart’s frame or steering wheel (recommended). From there, a wire (with connector) leads to
the engine casing, and is plugged in to the corresponding connector.
!TIP: when mounting the STOP button to a steering wheel, it is important to leave enough slack
to allow the wheel to turn, lock-to-lock, without pulling or binding the wire.
STARTER WIRE: SEE STARTER, 3.8
3.6
EXAUST MANIFOLD
The XR50’s exhaust manifold is fastened with 3 nuts, torqued to 25 Nm. copper-coated, self-
locking nuts are used to secure the header pipe.
ATTN: THERE IS NO EXHAUST GASKET
!TIP: you may use a high temp. silicon “liquid gasket” (sparingly).
3.7
EXHAUST PIPE
The exhaust pipe (or muffler) is fastened to the exhaust manifold with tension springs (2 incl.
with XR50 engine package) in a manner similar to other racing karts.
!TIP: replace the intermediate plastics in the exhaust mount with a strong compression spring
(due to extreme temperatures).
ATTN: EXHAUST PIPE MUST BE ASSEMBLED WITHOUT STRESS LOADS
ATTN: THE EXHAUST RUNS VERY HOT, AND TYPICALLY GLOWS RED - BURN HAZARD
!TIP: use 2 support brackets (due to added weight of exhaust system).
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
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ASSEMBLY PROCEDURES
(continued)
3.8
STARTER
The standard XR50 engine is started using an external starter placed over the clutch fastening
nut (with a 22 mm socket) or started with an optional on-board starter.
3.8.1
OPTIONAL ON-BOARD STARTER
RENNtech’s optional on-board starter is intended for use in short start intervals. Under normal
conditions, the motor should crank and start almost immediately.
3.8.4
ELECTRICAL CONNECTION
The optional starter motor is a 12V system, controlled via relay.
ATTN: DO NOT CRANK MOTOR USING STARTER FOR MORE THAN 10 CONSECUTIVE SECs.
!TIP: on-board starter should not be used for initial start-up during break-in period. External
starter is recommended until engine “loosens up” and starts easily.
!TIP: check all positive connectors and shield against accidental grounding.
3.8.2
EXTERNAL (or “REMOTE”) STARTER
ATTN: DO NOT CRANK MOTOR USING STARTER FOR MORE THAN 10 CONSECUTIVE SECs.
!TIP: once the engine starts, remove the starter socket IMMEDIATELY to avoid nut loosening.
!TIP: check central nut for tightness after each run when external starter is used.
!TIP: complete COLEMAN starters available through RENNtech INC.
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
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