750RK (Seca)

Electrical Maintenance


A. Battery

1. The fluid level should be between the upper and lower level marks. Use only distilled water if refilling is necessary.


Normal tap water contains minerals which are harmful to a battery; therefore, refill only with distilled water.



General Specifications



Basic color

New Yamaha Black or Brilliant Red


Cylinder Head and Valves -- Inspection & Repair


A.   Cylinder Head Cover

Place head cover on a surface plate. There should be no warpage. Correct by re-surfacing as follows:

Place #400 or #600 grit wet sandpaper on surface plate and re-surface head cover using a figure-eight sanding pattern. Rotate head cover several times to avoid removing too much material from one side.


Pistons and Cylinder Reassembly

11. Pistons and Cylinder a. Install the pistons on the rods. The arrow on the piston must point to the front of the engine.


Before installing the piston pin clips, cover the crankcase with a clean rag so you will not accidentally drop the circlip into the crankcase. Always install new piston pin circlips.


Crankshaft, Con rods and Bearings -- Inspection and Repair

I. Crankshaft

1. Crankshaft run-out

Support the crankshaft at both ends on V-blocks. Measure the amount of crankshaft run-out on the main bearing journals with a dial gauge while rotating crankshaft.

Run-out limit: 0.040 mm (0.0016 in!

If run-out exceeds limit, replace crankshaft.

2. Inspection of bearings


Middle Gear -- Inspection and Repair

P. Middle Gear

1. Damper disassembly


Disassembly of the middle gear damper requires the damper compressor (special tool) and a hydraulic press.

a. Place the middle drive shaft in a press with the damper compressor (special tool) in place as shown.

1. Damper compressor


Cylinder Head and Camshaft Reassembly

12. Cylinder head and Cam shafts 

a. Install the new cylinder head gasket. Install the dowel pins and "O-rings". Locate the cam chain cavity cylinder seal with the tabs down.

b.   Install the cylinder head onto the cylinder. Pull the cam chain through the cylinder head as it is installed. Tie the cam chain so that it does not fall into the crankcase.


Engine Maintenance





A. Valve Clearance Adjustment



Front Forks

XJ750RH Front Fork Disassembly/Reassembly

The XJ750RH front fork has a top and bottom bushing for the inner tube to ride in (reducing friction). Since the top bushing is pressed into the top of the outer tube, it is necessary to remove the oil seal before the inner tube may be removed from the outer tube. The procedure is as follows:


Piston, Pickup Coil, Shifter, Starter, Generator and Clutch Removal

C. Piston

1.   Mark each piston to aid in reassembly.

2.   Place a clean towel or rag into the crank-case to keep circlips and material from falling into the engine.

3.    Remove piston pin clips, piston pins, and pistons.

D. Pick-up Coil Assembly