148 – Precaution To Users of Leg Shields – Splash Shields – Large Wind Shields

PRECAUTION TO USERS OF LEG SHIELDS – SPLASH SHIELDS –
LARGE WIND SHIELDS

We sell these accessories to riders for protection from wet and cold weather. However, we must warn them against the
danger of injuring their engines if they ride their motorcycles too fast when equipped with the above-mentioned
accessories, particularly the fabric splash shields or metal leg shields.
The passage of air around the cylinder and cylinder head cooling fins is restricted to the extent that it is similar to operating an automobile without a fan belt or without water in the radiator; that is, the cylinder and cylinder head temperature will rise much higher than it does under normal operating conditions.
The rolling resistance built up by a head wind against the large wind shield causes the engine to labor abnormally,
which also contributes to this over-heating condition.
The first warning of insufficient cooling is the extraordinary heat radiating from the right side of the engine.
The second warning is “pinging”, pre-ignition of the spark plugs, which causes the engine to slow down.

THE FOLLOWING PRECAUTIONS SHOULD BE TAKEN TO PREVENT SERIOUS DAMAGE TO THE ENGINE:

1. Do not ride mile after mile over 50 m.p.h. (solo) 45 m.p.h. (sidecar) when the temperature is above 40°. ( If it is necessary to ride above these speeds, we suggest that you remove the right leg shield.)
2. Back off the throttle when you feel the heat on the right side of the engine or when you hear the engine “ping”. (Cruise a.t a speed where the engine doesn’t ping”.)
3. Do not use a “hotter” spark plug than Indian “C”. (Use Indian “D” if the ease of starting is not affected when the engine is cold.)
4. Do not run on “too lean” a mixture to save gasoline.
5. Clean gasoline filter frequently to assure an unrestricted flow of gasoline to the carburetor bowl.

When these precautions ere taken, a rider can enjoy the protection from the weather that these shields afford without
injuring his engine; otherwise, he may experience any one or all of the following conditions:

1. Poor oil mileage.
2. Scored pistons and cylinder walls because there is not enough clearance to take care of the greater piston expansion due to higher than normal temperatures.
3. Burnt cylinder head at spark plug insert. The cylinder heads are heated to a certain temperature when the insert is installed, which is higher than normal running temperature and if the head temperature gets over this point, there is a possibility of the insert becoming loose and burning through.

INDIAN MOTOCYCLE COMP.A NY
Walter Brown
Service Manager