Johnson Service Bulletin SB-735 - Paint Burning on Gearcase Extension

September 16, 1959. Factory correction for paint discoloration on V4L and V4SL long-shaft extension castings, with water spray hole dimensions.

Johnson Motors Service Bulletin letterhead
September 16, 1959
Bulletin No. SB-735
Subject: PAINT BURNING - GEARCASE EXTENSION V4L - V4SL-10 thru 11B
Original factory dimensioned water tube drawing showing water spray hole positions for standard long shaft and converted engines
We have received reports from time to time concerning paint discoloration and burning on the long shaft extension casting of the V4L - V4SL-10 thru 11B engine.
To correct this condition we have redesigned the extension casting and drilled a water spray hole in the inlet water tube from the water pump.
This condition does not exist on all engines. However, to correct this condition if it does exist, it will be necessary to install the latest extension casting part number 307179 and drill the spray hole in the location on the water tube as shown. This spray hole is 3/32" in diameter and is located on the aft side of the water tube 180° to the port side from center and 7" from the end which is inserted in the top of the water pump. NOTE: - on standard length engines and engines which have been converted to long shaft the spray hole is located on the aft side of the water tube 2" from the end and 180° to the port side from center.
JOHNSON MOTORS
Jack Penland
Jack Penland Service Department
JP:eb
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