BMW R71 User manual

BMW R71 Sidecar Replica Instruction for Motorcycle
CONTENTS
1 MAIN STRUCTURAL AND PERFORMANCE DATA
2 RUNNING-IN OF MOTORCYCLE
3 OPERATION OF MOTORCYCLE
4 MOTORCYCLE COMPONENTS CHECKING AND ADJUSTING
5 MOTORCYCLE ELECTRIC SYSTEM
6 MOTORCYCLE LUBRICATING
7 LONG TERM STORAGE OF MOTORCYCLE
8 MOTORCYCLE PERIODIC MAINTENANCE
9 MOTORCYCLE TROUBLESHOOTING

1. MAIN STRUCTURAL AND PERFORMANCE DATA
1.1 Components
1.2 Main Dimensional Data

1.3 Main Weight Data
1.4 Main Performance Data
1.5 Modes and Technical Data of Main Parts

2. RUNNING-IN OF MOTORCYCLE
In initial operation period of engine, improper operation will speed up wering of parts
because the parts have not been completely run in. Therefore running-in must be done
for new motorcycle.
Running-in period is divided into two phases: The first phase is from 0 to 1000 km and
the second one is from 1000 to 2000 km.
During running-in period, top speed of the motocycle should not exceed limitations given
in the following table.
In order to limit the maximum speed of the motocycle in running-in period, the caps of
the two carburetters are provided with stop screws (see Fig.2).
The lifted height of throttle valve is limited by the crew. At each end of running-in
period, the stop screw should be cut off from the slotted position, as shown in Fig.2
Although the top screw can limit speed, it is necessary to control and operate the
motorcycle carefully in running-in Period.
Long distance driving is not allowed within 0 to 500 km running-in period to avoid engine
temperature rising. Keep on checking temperature of the engine, gear box, rear drive
and brake drum. In the meantime, check all parts and components for fixation, adjust
gap and tighten loosened parts in time.
Keep on checking quality of oil in crankcase in the running-in period. If viscosity
becomes worse, and metal particles are found in the oil within the desired travelling
mileage, the oil should be replaced with fresh one. After finishing the running-in period,
the oil in gear box and rear drive should be replaced in hot status. Normal oil refilling
and replacing should be performed according to the motorcycle lubrication table.
Try to avoid driving the motorcycle on bad road in the running-in period. It Is not
allowed to drive the motorcycle for long duration at high speed and under overloading
condition. Load can be increased gradually when the running-in period is nearly over.
The load should be increased gradually after finishing the running-in period. Only when
3000 km travelling is obtained, the motorcycle can run at top speed and with maximum
load.
On completion of running-in period, tighten the screw of cylinder cap in hot condition of
cylinder.

3. OPERATION OF MOTORCYCLE
3.1 Preparation Before Start
3.1.1 Gasoline filling
Before start, check gasoline and oil quantity first . Refill it if gasoline or oil is
insufficient . Fill gasoline directly through the filter to gasoline tank . The gasoline
level should be 15-20mm below the edge of filler port.
3.1.2 Oil filling
3.1.2.1 The oil level should be maintained between the upper and lower mark lines of oil
dipstick inside crankcase (see Fig.3 ) To measure oil, the threaded plug should not be
screwed in but be on the filler edge. The oil inside gear box and rear drive casing
should be filled to start of threads of the plug.
3.1.2.2 Before oil filling, check the oil drain threaded plugs for being tightened.
3.1.3 After gasoline and oil filling, check handle bar, brake and clutch for reliability
and flexibility. Check pressure of tyres, fixation of wheels, connection of sidecar to
main frame, electrolyte level of battery, and electric circuit and gasoline (oil) lines for
serviceability.
3.2 Engine Start
There are two kinds of starting devices for the engines listed in this instruction. One is
kickstarter and the other is starting motor and kickstarter. The engine can be started
on completion of the above preparation.
The following steps should be taken for "cold" engin starting.
3.2.1 Turn on the gasoline control knob.
This knob is a three-position one. Left position is ON position, right position is
STANDBY position ( when the knob is set to this position, motorcycle can run 30km
more) , and the down position is OFF position.

3.2.2 Set the hand gear shift lever or foot gear shift lever to neutral gear position
between gear positions No.1 and No.2 (see Figs 4 and 5). Check to see whether the gear
lever is at neutral positicn by stepping lightly the kickstarter . If the wheels wouldn't
move, the neutral gear position is properly set. If the wheels trend to move forward,
the neutral gear position is not properly set. 'I'hen it should be reset. The engine can
be started only when the neutral gear position is properly set.
3.2.3 Press down the button attached on the float chamber cover until the gasoline
spills out from the float chamber cover of the carburetter.
3.2.4 Close the air valve approximately by half (1/2).
3.2.5 Turn outwards the throttle twist grip to the end, then bring it back to 1/8 full
travel.
3.2.6 Step the kick starter for 4-5 times to make the crank shaft operate. The
cylinders suck in some mixed air and oil is supplied to part surfaces in advance which
need to be lubricated.

3.2.7 Cut-in the ignition switch by use of key (turn the key counterclockwise for
daytime driving and vice versa).
3.2.8 Press down the kickstarter slightly by foot to make the brake block insert into
the ratchet wheel of the starting gear (No idle travel is felt). Then starting can be
realized by stepping the kickstarter forcefully. If staring motor is used, first set the
levers to neutral positon. (see Figs 4 and 5),or hold the clutch lever with left hand to
disengage the clutch. Press the starting button with right hand (each press should not
take more than 3 seconds. Interval between two presses should not be less than 2
seconds. Restarting should be done one minute later after three successive presses).
Caution: If it fails to start by trying several times, it is forbidden to
successs-vely press the starting button or step the kickstarter. Otherwise it
will shorten the life of battery and starting mechanism.
3.2.9 After the engine is started, slowly open the air valve according to the engine
operating condition.
3.2.10 According to the operation sound of the engine, rotate the throttle grip to
warm up the engine at low speed and then drive the motorcycycle.
3.3 Astern driving of three-wheel motorcycle (with sidecar)
For astern driving operate as follows:
a. Stop the motorcycle.
b. Set the gear to position No. 1 (or neutral)
c. Apply the astern lever with teft tiptoe or left sole
to Astern position.
d. Drive astern the motorcycle with normal driving
method
Astern operation Positions are shown in Fig 6
3.4 Engine Shutdown
3.4.1 For engine shutdown, reduce the throttle, then
turn off the ignition switch.
3.4.2 After engine shutdown, take out the key and
set the gasoline control knob to OFF positicn. For long
period parking, the battery should be disconnected to
avoid electric leakage.
3.5 Parking in Severe Cold Season
In severe cold season, the following procedures
should be taken for parking the motorcycle outside.

3.5.1 Before parking, set the gasoline control knob to OFF and press down the float
button to make all gasoline remaired in the carburetter burnt out.
3.5.2 Remove the battery to prevent it from being damaged by frost.
NOTE : If starting motor is to be used due to engine flameout caused by
improper operation to the motorcycle, hold the clutch lever to disengage the
clutch, then start the engine with motor. It is not necessary to neutral
position for starting and the gear lever may be set at any position, but it is
better to be set at lower gear position so as to get smooth starting. If
kickstarter is to be used, starting can be performed only when the neutral
pesition is set.

4. MOTORCYCLE COMPONENTS CHECKING AND ADJUSTING
As the motorcycle had been adjused and tested before delivery, there is no need to
make any readjustment. In case there is any fault with the motorcycle, trouble
shooting should be performed as the following:
4.1 Spark Plug Gap Adjusting
When new spark Plug is used or after the motorcycle has been driven for1000 km,
spark plug gap should be checked with feeler gauge. If necessary, adjust the gap to
0.6-0.7mm.When the spark plug is needed to be cleaned, it should be cleaned in gasoline
with brush (use of metal wire brush is not allowed).
4.2 Mixture Valve Opening Checking and Adjusting
Inadequate valve opening will directly affect the engine power, which will cause
difficult starting, unsteady idling, high fuel consumption and poor acceleration. So the
valve opening must be properly adjusted.
4.2.1 Open the valve chamber cover (Item 4 in Fig-7 )
4.2.2 Apply kickstarter to operate engine crankshaft so as to make the cylinder to be
adjusted be in final compression position, i.e.inlet valve opens fully and comes down
completely.At this moment, the pisiton has gone through a complete operating cycle
(from upper limit point to lower limit point and then from lower limit point to upper limit
point) .
4.2.3 Move the adjusting screw (Item 2 in Fig.7) with screw driver and check the
opening, which should be 0.06mm for hot cylinder and 0.1mm for cold cylinder.
4.2.4 If opening does not meet the requirement, loosen nut (Item 1 in Fig.7) and
readiust the opening.
4.2.5 Check repeatedly according to para.4.2.2 and 4.2.3 and then tighten the nut.
4.2.6 Refit the valve chamber cover.
4.2.7 If the opening is still too wide , which can not be adjusted, the relative parts
such as tappet should be changed.

NOTE: The mixture valve opening for engine CJ-750D can be checked and
adjusted as follows:
a. Open the valve chamber cover ( Fig.7) remove rubber block (Fig.10) from
observation hole in crankcase, apply kickstarter to operate the crank shaft.
When inlet valve of left cylinder opens, apply gently kickstarter to make the
"O" scale line on flywheel be in the center of observation hole.
b.Loosen the locknut, adjust the adjusting screw to make the gap between
end of adjusting screw and inlet (outlet) valve be 0.07mm for hot cylinder
and 0.1mm for cold cylinder. Then tighten the locknut and recheck the valve
opening with feeler gauge.
c. Apply gently kickstarter to rotate the flywheel for 360 when the O scale
line of flywheel appears again in the center of observation hole, check and
adjust the right cylinder mixture valve opening with the above method.
4.3 Distributor Platinum Contact Gap Checking and Adjusting
The distributor should be kept clean. The platinum contact should be free from dust
and lube (oil) contaminaton. The contacting area of the contact should not be less than
80% and the centers of upper and lower contacts should align with each other.
4.3.1 The distributor of engine CJ-750, installed in the front end cover of crankcase,
is of FDQ-1 type, whose contact gap is adjusted as follows (see Fig.8).
4.3.1.1 Remove crankcase front cover and distributor cover.
4.3.1.2 Rotate camshaft to a certain position by applying kickstarter and take off
distributor disk.
4.3.1.3 Rise camshaft by applying kickstarter to separate platinum contacts.