4. Maintenance
USE AND MAINTENANCE MANUAL
CHAPTER 4
MAINTENANCE
4-Strokes - Edition 00 / 2022
120
FWD
x2
x4
1
2
4
5
3
6
4
3
2
1
3
2
2
1
1
3
Removal (XXF 450 / XEF 450 versions)
– Remove: Seat, left and right conveyors, air filter casing, fuel
tank;
– Remove the spark plug and valve cover;
– Remove the camshafts (refer to chapter ”4.4 Camshafts”
on page 108);
– Remove the nuts and bolts securing the head to the cylinder;
Loosen the bolts ½ turn at a time, following the
sequence shown in the figure.
– Remove the bolts after having completely loosened each
one.
M6 x 35 mm (1.38 in): “1”, “2”,
M10 x 149 mm (5.87 in): “3”, “4”, “5”, “6”
– Remove head “1” from the cylinder, gasket “2”, centering
pins “3” and timing chain guide “4”;
Check (XXF 450 / XEF 450 versions)
– Remove carbon deposits using a rounded scraper;
Take care to avoid damaging the spark plug threads.
Do not use a sharp instrument. Avoid scratching the
aluminum.
– Check the head for damage and/or cracks, if any, replace
the head;
– Check the water circuit, if there is encrustation and/or rust
replace the head;
– Measure the deformation of the head, if it does not conform
to specifications, level the head.
Maximum permissible deformation:
0.05 MM (0.0020 in)
If it is necessary to replace the head, the valves must
also be replaced.
Installation (XXF 450 / XEF 450 versions)
– Wash the threads and contact surfaces of bolts, washers,
head/cylinder contact surface and crankcase threads;
– Install the gasket, centering pins, timing chain guide and
head;
– Apply molybdenum disulphide grease to the threads and
contact surfaces of the bolts and washers;
– Install washers “1”, bolts “2” and nuts “3”.