All You Need to Know About CISON L4-175 OHV Inline 4 Engine | StIirlingkit

All You Need to Know About CISON L4-175 OHV Inline 4 Engine | StIirlingkit

All You Need to Know About CISON L4-175 OHV Inline 4 Engine | StIirlingkit

Instruction Manual updated automaticlly if there is any change: click here


Parameter description

.Brand: CISON
.Model: L4175-OHV
.Cylinder: in-line four cylinder
.Displacement: 17.5cc
.Stroke: Four-stroke
.Bore: 16.7mm
.Stroke: 14mm;
.Speed: 1500-8500rpm
.Starting power: 2S-3S lithium batter; 6-14V, 12V Li battery is recommended 
.CDI power: 2S-3S .
.Initial oil needle: 1.5 turns of main oil needle, 0.8 turns of auxiliary oil needle,
and 1.3mm of air valve


 Igniter CDI


a. Please open the ejector rod / valve observation window first
b. Look at the picture on the CDI and find the first cylinder
c. Rotate the flywheel anticlockwise and observe the inlet valve of cylinder 1. After the
inlet valve is opened, continue to rotate the flywheel to the upper dead center
(compression point of the first cylinder). At this time, keep the flywheel still
d. install CDI magnet (with color) on the crankshaft pulley (foam: 27
The magnetic pole of faces Hall)
Note: the magnet installation must not protrude, otherwise it may collide with the engine
screw. (option 2: add shims when installing the pulley (27))
e. At this time, install the fixing screw of the upper belt pulley. Please do not fix the
belt pulley
f. The rotating pulley magnet triggers the hall closest to the bottom. 

2. High voltage line

a. Observe the pictures on the CDI, check the cylinder sequence, and insert the high-voltage wire accordingly.

Note: the high-voltage wire does not directly contact the spark plug. Please keep the distance between the high-voltage wire and the spark plug less than 2mm, otherwise it may be damaged sensor.

3. Ground wire
a. The black wire on the CDI needs to be connected to the engine block to ensure the high-voltage circuit. Otherwise the sensor will be damaged

Before preparing for operation

be careful!:
1. Forcibly starting the machine without running in may cause the starting motor to overheat and burn.
2. It is recommended to add 15ml~18ml lubricating oil to the oil pan (10w50 recommended, for special cases
1. Oil pump adjustment
a. Please connect the oil pipe correctly first
b. Please install the oil flow adjusting screw
c. Please adjust the oil flow according to the internal oil pipe from near to far (the closer to the oil pump , the smaller the flow should be, otherwise there may be no oil in the farthest oil hole) 
d. It is recommended not to install the crankcase side cover (foam No.: 04, 05) at first. During running in, observe whether there is splash of lubricating oil to facilitate flow adjustment.
2. Since the new machine has not been run in, the engine resistance will be
relatively large. Please carry out the following operations first
a. Remove spark plugs
b. Please adjust the oil pump correctly
c. When installing the starting motor, first use the DC 6-8v power supply for pressure free running in (Note: the starting motor cannot run for a long time, and this step can be ignored if a single piston ring is used)
d. After running in smoothly, install 2 spark plugs and start the motor again. If the engine can be easily driven, continue to install the remaining 2 spark plugs and run the starter again. If it can be easily driven, the cold running in is successful, Otherwise, please insert and remove the spark plug to continue running in (pay attention to lubrication during running in, and add a small amount of lubricating oil to the cylinder liner)
be careful!:
1. Forcibly starting the machine without running in may cause the starting motor to overheat and burn.
2. It is recommended to add 15ml~18ml lubricating oil to the oil pan (10w50 recommended, for special cases Other labels are also acceptable)

CDI conntction diagram.

If there is no series resistance between the high voltage wire and the
spark plug of CDI, the noise that interferes with the sensor may be
generated, causing four high voltage wires to generate sparks at the
same time,But this will not affect the operation.
But I suggest you connect the resistance we provide in series between
the end of the high-voltage wire and the spark plug. 

Why can't CISON CISON L4-175 OHV engine start?

  1. The spark plug is not tightened, resulting in insufficient cylinder compression. 
  2. There is foreign material present in the valve, resulting in a cylinder leak and low compression.
  3. The ignitor Angle is not set well: after seeing the inlet valve open and go down, look at the spark plug hole or use non-metallic materials to reach the top dead center, and do not move the flywheel at this time. Using a marker, draw a line directly between the flywheel shell and the flywheel. Then unscrew the crankshaft pulley, keep the flywheel stationary or let the flywheel return 5-10° clockwise (ignition advance), then plug in the high voltage cap and hall according to the mark on the CDI, and connect the power cord and ground cable properly. Then watch from the flywheel side and turn the belt wheel counterclockwise so that the magnet on the belt wheel reaches a hall near the oil pan until you see a high pressure spark in the 1 cylinder high pressure cap. At this time, fix the flywheel and belt pulley, and lock the belt pulley fixing screws (it is recommended to add a little low strength screw glue to prevent the belt pulley loosening). At this time, turn the flywheel clockwise and observe whether the high pressure spark appears at the TDC scale or the advance Angle marked by you. If it appears, the setting is successful.
  4. The cylinder pressure is low when the double cast iron piston ring is used for the first time, and a certain amount of lubricating oil is needed to supplement it. Please add 30ml lubricating oil to the cylinder block for the first time to make it fully lubricated. 

  5.  The old version of O-ring piston ring is used, and 16*1 leads to great piston resistance (when the starter motor is replaced, a new 15.5*1 O-ring has been reissued to them, and it will be very smooth after being installed)

  6.  When using cast iron piston ring, the motor speed is too low or the voltage is low.

  7. Carburetor issue:If the carburetor's internal oil sump is filled with excessive oil, it can cause the cylinder to become submerged, leading to engine start failure. To address this, first, turn off the fuel tank. Then, partially unscrew the bottom screw of the carburetor to allow the excess oil to drain slowly through the overflow pipe until it is completely emptied. Once drained, reseal the fuel tank and tighten the screw. 







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