1901-1953 Indian Motorcycle – Parts – Accessories

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72 – Servicing the 1937 45 and 74 Clutches

72 – Servicing the 1937 45 and 74 Clutches

1937, 45’s and 74s’ have been built with clutch spring pressures to take care of commercial as well as solo and side car work.
A smoother operating clutch with increased pedal pressure may be obtained by reducing this spring pressure for solo, side car and city police.
The following is recommended:

1- Remove six (6) springs from clutch leaving ten (10)
2- When it is down remove moulded discs and dip in “Oil Bag” or a similar graphite oil before reassembling.


Idle characteristics and smooth running of four cylinder machines with
twin carburetors at low speeds is often affected by the relative positions of the carburetor throttle valves. To obtain the correct position of each valve with respect to the ether valve adjust as follows.

1 Start motor.
2 Loosen binding screw that holds rear carburetor throttle lever to the
throttle shaft.
3 Adjust front carburetor throttle lever stop screw until good idle is obtained. During this operation hold rear throttle shaft in closed position.

4. Adjust rear carburetor throttle lever stop scrow until good idle is ob­tained.

5- Tighten rear carburetor throttle lever binding screw being sure position of valve does not change.
6- Adjust idle mixture screw to obtain correct idle mixture.
7- Readjust throttle lever stop screws on both carbu1·etors the same amount to get correct idle speed.
8- Be sure all air leaks in Manifolds and Compensator line are eliminated

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