Rover RM 33 LS, Operator'S Manual

Service

7

18

Flexible Pump Coupler

The flexible pump coupler is a nylon “spider” insert, located 

between the pump and the engine shaft. Over time, the coupler 

will harden and deteriorate. Replace the coupler if you detect 

vibration or noise coming from the area between the engine and 

the pump. If the coupler fails completely, you will experience a 

loss of power.

NOTE: 

Never hit the engine shaft in any manner, as a blow will 

cause permanent damage to the engine.
1. 

Disconnect the spark plug wire and ground it against the 

engine.

2. 

Remove the three flange lock nuts and hex screws that 

secure the pump to the coupling shield. Two flange lock 

nuts and hex screws are at the bottom corners and one is in 

the top center. See Figure 7-1.

.0600

.0100

Flange

Lock

Nuts

Hex Screw

Set Screw

Bottom View

Figure 7-1

3. 

Remove the pump.

4. 

Loosen the set screw on the pump coupling half and 

remove the coupling half.

5. 

Rotate the engine by slowly pulling the starter handle until  

the engine coupling half set screw is at the bottom. Loosen 

the set screw using an allen wrench and slide the coupling 

half off the engine shaft.

6. 

Slide the new engine coupling half onto the engine shaft 

until the end of the shaft is flush with the inner portion 

of the coupling half. (There must be space between the 

end of the engine support bracket and the coupling half). 

Tighten the set screw.

7. 

Install the nylon “spider” onto the engine coupling half.

8. 

Install the pump coupling half and key on the pump shaft. 

Rotate the coupling half until the set screw faces down. Do 

not tighten set screw.

9. 

Align the pump coupling half with the nylon “spider” by 

rotating the engine using the starter handle. Slide the 

coupling half into place while guiding the three mounting 

bolts through the holes in the pump support bracket.

10.  Secure with the nuts removed earlier.
11. 

Set .0100” to .0600” of a clearance/gap between the nylon 

“spider” and the engine coupling half by sliding a feeler 

gauge or matchbook cover between the nylon “spider” and 

the engine coupling half and moving the pump coupling 

half as needed. Secure the pump coupling half with the set 

screw. See Figure 7-1.

NOTE: 

Make certain the proper clearance/gap is obtained 

before tightening the set screw.

12.  Reconnect the spark plug.