Sealey MS100 Instructions Manual

INSTRUCTIONS FOR:

MOTORCYCLE COMPRESSION AND
FUEL PRESSURE GAUGE 3PC
MODEL No: MS100

1. SAFETY INSTRUCTIONS

IMPORTANT: Always refer to the vehicle manufacturer’s
service instructions, or proprietary manual to establish the
current procedure and data.These instructions are
provided as a guide only.

 WARNING! Ensure all Health and Safety, local authority,
and general workshop practice regulations are strictly
adhered to when using product.

 Maintain tools in good and clean condition for best and
safest performance.DO NOT use test kit if damaged.
 Account for all tools and parts being used and do not leave
them in, or on the engine after use.
 Ensure you have read and understood the safety aspects of
dealing with the fuel injection system and petrol in general
before commencing.

Fuel Hazards:

 WARNING! Petrol fumes and battery gases are explosive.
 DO NOT smoke or allow an open flame or sparks in the

work area.
 Keep a dry chemical (class B) fire extinguisher near to the
working area.
 Avoid fire hazard by using caution when disconnecting fuel
lines and installing adaptors - some spillage is inevitable.
 When connecting to or disconnecting from a fuel system,
relieve pressure from system and wrap a cloth around the
fuel line fitting to absorb any fuel leakage. Wipe up fuel

spills immediately.

Fuel Leaks

 Constantly check gauge and adaptor connections for
leakage. If you see leakage turn off the ignition or disable
the fuel pump, relieve fuel pressure if necessary and correct
leaks before continuing.

 DO NOT let fuel drip or spill onto a hot engine.
 Wipe up fuel spills immediately.
 When using tee adaptors, secure hose with hose clamps to

ensure leak-free connections.
 Check all adaptor sealing washers and 'O' rings are in good
condition before use.
 DO NOT allow fuel to remain in the adaptors or hoses after
use.

Personal / Operation

 Wear approved eye protection. A full range of personal
safety equipment is available from your Sealey dealer.
 Keep yourself, clothing and test equipment away from all
moving or hot engine parts.

 Do not wear jewellery and tie back long hair.
 Before performing a test with the engine running (unless

the manufacturer's manual states otherwise), set the
parking brake and place the gear selector in neutral or
park, and block the drive wheels.
 Exhaust gas contains deadly poisonous gases. The test
area must be well ventilated - route the exhaust gas outdoors.
 Before repairing the fuel system, turn off the ignition switch
and disconnect the battery per manufacturer's procedure.
 Never disconnect the battery whilst the engine is running.

Thank you for purchasing a Sealey product. Manufactured to a high standard this product will, if used according to these instructions
and properly maintained, give you years of trouble free performance.

IMPORTANT: PLEASE READ THESE INSTRUCTIONS CAREFULLY. NOTE THE SAFE OPERATIONAL REQUIREMENTS, WARNINGS AND CAUTIONS.
USE THE PRODUCT CORRECTLY AND WITH CARE FOR THE PURPOSE FOR WHICH IT IS INTENDED. FAILURE TO DO SO MAY CAUSE DAMAGE
AND/OR PERSONAL INJURY AND WILL INVALIDATE THE WARRANTY. PLEASE KEEP INSTRUCTIONS SAFE FOR FUTURE USE.

 WARNING! DO NOT use this kit or the components from this kit on diesel fuel systems or high pressure petrol injection systems
(in excess of 145psi). Ensure you have read and understood the safety aspects of dealing with the fuel injection system and petrol in
general before commencing.

2. INTRODUCTION

Set of three gauges with connectors and adaptors for testing compression
and fuel pressure on motorcycles. Gauges range from 0-300psi for
compression testing , 0-7bar (0-100psi) for fuel pressure and 0-1bar
(0-100kPa) for low pressure fuel.

Model No: .................................MS100

Spark Plug Sizes: ..........................8, 10, 12, 14

Hose Lengths: .............................220mm

Fuel Connector Sizes: ......................Ø 6.4, 7.9mm

Original Language Version

© Jack Sealey Limited

MS100 Issue 2 (P) - 17/07/13

3. OPERATION

3.1 Procedure for Compression Test

 WARNING! Always release the pressure via the Release Valve before disconnecting the tester.
Press the release valve slowly to release the pressure gradually. Refer to Fig.1.

NOTE! A variation in compression readings between cylinders is often a better indication of engine problems than the absolute
values of compression.

3.2 Run the engine until it reaches the normal operating temperature.

3.3 Stop the engine and disconnect all spark plug wires, numbering them according to the cylinder to which they were

connected.

3.4 Loosen all spark plugs by about half a turn, but do not remove them.

3.5 Using an air hose or wire brush, remove all the dirt and debris from the spark plug wells.

3.6 Remove the spark plugs and place them on a clean, flat surface in the cylinder order in which they were removed.

3.7 Remove the air filter.

3.8 Disconnect the ignition system, following the manufacturer’s recommendations in the vehicle servicing manual.

3.9 Select the spark plug adaptor required for the vehicle. Screw the adaptor to the hose. Screw the spark plug adaptor and hose assembly into
a spark plug well. Hand tighten only. DO NOT use a wrench. Refer to Fig.2.

3.10 Connect the coupling on the gauge to the hose. Ensure the coupling is fully engaged.

3.11 Crank the engine for at least five compression strokes, or until the pressure reading on the gauge stops rising, with the throttle in the wide

open position.

3.12 Record the compression reading, then push the side release valve to relieve the pressure.

3.13 Repeat the test and record the reading. Relieve the pressure and remove the hose and adaptor from the spark plug well.

3.14 Repeat for the remainder of the cylinders.

4.1 Compression Gauge Readings

4.2 On a normal cylinder, the gauge needle should travel up the scale on each compression stroke until it reaches peak value. All cylinders

should indicate a pressure that is within the vehicle manufacturer ’s specifications, and the reading should not vary by more than 10% from
cylinder to cylinder.

4.3 If the gauge needle does not travel up the scale or if it remains at the same value for several strokes and then starts to climb, the problem
could be a valve sticking.

4.4 If the compression reading is considerably higher than the vehicle manufacturer’s specification, the problem may be carbon build-up in the
cylinder. It may also indicate that either the piston, or the cylinder head, has been modified.

4.5 If a reading on two adjacent cylinders is 20psi (or more) lower than the other cylinders, the problem may be a cracked cylinder head or
defective main gasket. Under these conditions, both coolant and oil may be found in both cylinders.

4.6 If the readings are low, or vary widely between cylinders, pour a teaspoon of SAE 30 oil into each cylinder and retest them. If the readings
increase considerably, the problem may be poorly seated, or worn, piston rings. If the readings remain about the

same, the valves and/or

associated components may be the problem. A burned or damaged piston may also cause the same results.

5. COMPLETION OF TEST

4. TEST RESULTS

5.1 Clean, re-gap and reinstall the spark plugs in the same order in which they were removed, or install new spark plugs.

5.2 Reconnect each spark plug wire to the plug it was connected to prior to removal.

5.3 Return the throttle plates to the closed position.
 IMPORTANT: After test, failure to return the throttle plates to the closed position before
starting the engine can cause serious damage to the engine.

5.4 Reconnect the ignition system wiring disconnected in paragraph 3.8.

Fig.1

Fig.2

Original Language Version

© Jack Sealey Limited

MS100 Issue 2 (P) - 17/07/13