GS/GSX/GSX-R#139 Revised: GS500FK4/K5 Engine Knock At Idle

[Fred]

SUBJECT: GS500F ENGINE KNOCK AT IDLE
AFFECTED UNITS: GS500FK4/K5 - ENGINE NUMBER M504-125865 & EARLIER
REFERENCE: GS500 SERVICE MANUAL (PN 99500-34094-03E)
NOTICE:
This bulletin is a revision to the original Service Bulletin GS/GSX/GSX-R NO. 139 dated
5/2/2005. Please place a copy of this bulletin with your dealership’s Service Bulletin binder
and GS500 Service Manual and discard the original bulletins.
Some GS500FK4/K5 motorcycles may exhibit a mild but annoying knocking noise from
the cylinder head area. This sound will be heard only at idle or just off idle.
Solution
This knocking noise may be caused by the camshafts walking side to side during operation
due to excessive end play. The “walking” movement will not cause damage.
Note: Test the source of the noise for camshaft “walking” by carefully leaning the
motorcycle over to the left (toward the sidestand) while the engine is running and continue
to listen for the noise. The noise will quiet if the camshafts are loaded toward the left hand
side.
Should you receive a complaint of the above described symptoms, follow the procedure
in this Service Bulletin.