5005554 JOHNSON CARBURETOR Assy, 150 - Port

Table 1
Required Tools
Tool Part Number Part Description Qty
A 7F-4292 Valve Spring Compressor 1
9U-6144 Adapter 1 Start By:
Remove the rocker shaft and push rod. Note: Refer to Specification UENR3421 "Engine Design" for non-specified engine Torque Values.Note: The following procedure should be adopted in order to remove the valve springs when the cylinder head is installed to the engine. Refer to Disassembly and Assembly, "Inlet and Exhaust Valves - Remove and Install" for the procedure to remove the valve springs from a cylinder head that has been removed from the engine.Note: Ensure that the appropriate piston is at top dead center before the valve spring is removed. Failure to ensure that the piston is at top dead center may allow the valve to drop into the cylinder bore.
Illustration 1 g02799356
Illustration 2 g02725099
Personal injury can result from being struck by parts propelled by a released spring force.Make sure to wear all necessary protective equipment.Follow the recommended procedure and use all recommended tooling to release the spring force.
Ensure that the valve spring is compressed squarely or damage to the valve stem may occur.
Follow Step 1.a through Step 1.d in order to position the appropriate piston at top dead center.
Install Tooling (A) in position on the cylinder head in order to compress a valve spring (4) for the appropriate piston.
Use Tooling (A) in order to compress valve spring (4) and open the valve slightly. Note: Do not compress the spring so that valve spring retainer (3) touches the valve stem seal.
Rotate the crankshaft carefully, until the piston touches the valve. Note: Do not use excessive force to turn the crankshaft. The use of force can result in bent valve stems.
Continue to rotate the crankshaft and gradually release the pressure on Tooling (A) until the piston is at the top dead center position. The valve is now held in a position that allows the valve spring to be safely removed. Note: If all valve springs require replacement, the procedure can be carried out on two cylinders at the same time. The procedure can be carried out on the following pairs of cylinders. 1 with 4 and 2 with 3. Ensure that all of the valve springs are installed before changing from one pair of cylinders to another pair of cylinders.
Do not turn the crankshaft while the valve springs are removed.
Remove valve cap (1). Apply sufficient pressure to Tooling (A) in order to allow removal of valve keepers (2). Note: Do not compress the spring so that valve spring retainer (3) touches the valve stem seal.
Slowly release pressure on Tooling (A).
Remove valve spring retainer (3) and remove valve spring (4).
Illustration 3 g02725101
Remove Tooling (A).
Remove valve stem seals (5).
Repeat Step 2 through Step 5 in order to remove the remaining valve springs from the appropriate cylinder. Installation Procedure
Install the inlet and exhaust valve springs in the reverse order of removal.
Illustration 4 g02862476
Install valve springs with the smaller pitch end (6) downward on cylinder head side.
Inspect valve springs (4) for damage and for the correct length. Refer to Specifications, "Cylinder Head Valves " for further information.