Valve Clearance; Checking And Adjusting Valve Clearance - BRP Johnson 4HP Service Manual

PERIODIC MAINTENANCE

VALVE CLEARANCE

VALVE CLEARANCE
Inspect initially after 10 hours (1 month) and every 200
hours (12 months) thereafter.

Checking and Adjusting Valve Clearance

Checking
1. Remove the following parts:
•
Engine cover
•
Recoil starter
•
Spark plug
•
Engine cover seal
2. Remove the four bolts 1 and the cylinder head cover 2.
3. Rotate the flywheel clockwise to bring the piston to Top
Dead Center (TDC) on a compression stroke.
Rotate the crankshaft clockwise to prevent water pump
impeller damage.
NOTE:
•
To confirm whether the piston is at the TDC position on a
compression stroke or on a exhaust stroke, rotate the fly-
wheel within ±15° beyond the TDC position.
•
If both rocker arms do not move at all, the piston is at the
position on a compression stroke.
•
If any rocker arm moves, the piston is at TDC on a exhaust
stroke. Rotate the flywheel one more turn.
•
The valve clearance specification is for COLD engine con-
dition.
2-10