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5-13E
1
2
3
4
– Take the valve spring retainer
1
and the valve springs
2
out of the
cylinder head.
– Pull the valve stem gaskets off the valve guides and remove the
spring seats
3
.
Sealing surface
Check the spark plug thread and the valve seats for damage and cracks.
Use a ruler and a feeler gauge to check the sealing surface of the
cylinder head for distortion. Max. distortion: 0.10 mm.
Valve guides
The valve guides are checked with a limit plug gauge 590.29.026.006
4
(Ø 6.05 mm). If the limit plug gauge can be easily inserted into the
valve guide, the guide must be replaced in a specialized workshop.
Valve seats
The valve seats must not be "battered". Sealing seat width:
inlet: 1.50 mm max.; outlet: 2.00 mm max. If necessary, the valves
must be reseated.
Valves
Check the valve disc for wear and eccentricity. Max. eccentricity at valve
disc: 0.03mm. The valve seat must not be "battered". The sealing
surface should be in the middle of the valve seat. The valve stem is
chrome-hardened; by experience, wear occurs at the valve guide.
Valve springs
Check the valve springs for fractures or wear (visual check); use a sliding
caliper to measure the length. Replace the spring if it is shorter see
Technical Data – also see Technical Information 0003/30/02.
Valve stem gaskets
Every time the valves are dismounted you should replace the valve stem
gaskets.
– Place the 4 spring seats
3
into the cylinder head.
– Slip the valve stem gaskets onto the valve guides and oil them.
– Thoroughly oil the valves at the stem and insert them into the valve
guides. When mounting them, watch for the correct position of the
valves.
– Position the valve springs
2
, place the valve spring retainer
1
into
the valve springs.
NOTE: The outer valve springs must be mounted
with the more narrowly wound end facing
downward (up to model 2001).
– Preload the valve springs with the special tool and mount the valve
keys.
NOTE: When mounting the valve keys ensure their proper fit. It is best
to secure the valve keys to the valve by means of some grease.
– Finally, use a plastic hammer to tap several times onto the valve
spring retainers.
Summary of Contents for 250 EXC
Page 59: ...ENGLISH 58 ...
Page 60: ...ANHANG APPENDICE APPENDIX APÉNDICE 1 SCHALTPLAN WIRING DIAGRAMM ...
Page 61: ...ANHANG APPENDICE APPENDIX APÉNDICE 2 SCHALTPLAN WIRING DIAGRAMM ...
Page 62: ...ANHANG APPENDICE APPENDIX APÉNDICE 3 SCHALTPLAN WIRING DIAGRAMM ...
Page 92: ...2 7E 1 2 3 4 21 23 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 5 22 24 ...
Page 172: ...8 3E CARBURETOR KEIHIN FCR MX 37 39 41 ...
Page 242: ...Repair manual KTM 250 610 Racing Art Nr 3 206 023 E 12 2E ...
Page 243: ...12 3E ...
Page 244: ...12 4E Repair manual KTM 250 610 Racing Art Nr 3 206 023 E ...
Page 245: ...12 5E ...
Page 246: ...Repair manual KTM 250 610 Racing Art Nr 3 206 023 E 12 6E ...
Page 247: ...12 7E ...
Page 248: ...Repair manual KTM 250 610 Racing Art Nr 3 206 023 E 12 8E 250 400 520 MXC EXC RACING 2002 ...
Page 249: ...12 9E Modell 250 400 520 EXC RACING ...
Page 250: ...Repair manual KTM 250 610 Racing Art Nr 3 206 023 E 12 10E 250 400 520 EXC RACING 2002 ...
Page 251: ...250 450 525 MXC EXC 01 02 03 12 11E ...
Page 252: ...12 12E Repair manual KTM 250 610 Racing Art Nr 3 206 023 E ...
Page 253: ...12 13E 250 450 525 EXC Racing 2003 ...
Page 257: ...12 17E ...
Page 258: ...12 18E Repair manual KTM 250 610 Racing Art Nr 3 206 023 E ...