September 16, 1959
Bulletin No. SB-738
Subject: TEST WHEELS 40 and 75 H.P. ENGINES -
You have recently been informed regarding the
addition of the 40 and 75 H.P. engine to the
JOHNSON line for 1960.
These two engines naturally require special test
wheels for tank testing. The enclosed order form
covers these two test wheels. The price and part
numbers are as follows:
Part No. H.P.
378088 40 Engine $4.50 net f.o.b. Galesburg
378046 75 Engine $4.50 net f.o.b. Galesburg
Your order must be submitted to:
JOHNSON MOTORS
SERVICE DEPARTMENT
When tank testing the larger horsepower engines,
running time at full throttle must be held to a
minimum. Running these engines at full throttle
for extended lengths of time can be damaging as a
result of overheating. The overheating will take
place due to the turbulence set up by the test
wheel and exhaust blast. The presence of such
turbulence will cause excessive air bubbles at the
water intake, resulting in air pockets or voids in
the cooling water supplied by the pump.
NOTE: Do not attempt to test the 75 H.P. Engine
in the small Stolper test tank.
When testing the larger horsepower engines prior to
sale or after repairs, run at full throttle only
long enough to make the necessary carburetor adjust-
ments. After adjustments have been made, reduce the
engine speed to approximately one half throttle, or
to a point where the tank turbulence has been brought
to a safe level. Under no circumstances should you
attempt to break in the 75 or 40 H.P. engine in a
test tank.
JP:eb
NOTE: Post on RD & V4 series index.
JOHNSON MOTORS
Jack Penland
Jack Penland
Service Department