Derbi ATV DXR 200, Workshop Manual

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75
NOTE
PROBLEMS SHOOTING
<Q-A> Compression too low?
- worn, stuck, or broken piston rings
- worn or damaged cylinder or piston
<Q-A> Compression too high?
- excessive carbon build-up in combustion chamber or on piston head
<Q-A> White smoke from exhaust muffler?
- worn or damaged cylinder or piston
- worn or damage piston ring
<Q-A> Abnormal noise - piston?
- worn or damaged cylinder, piston, or piston ring
- worn piston pin or piston pin hole
4-5-1. Cylinder removal (Fig. 4-54)
01. remove the cylinder head
02. remove the cylinder head dowel pins
03. remove the 2 bolts and remove the cylinder (1)
4-5-2. Cam follower removal Fig. 4-55
01. remove the cam follower shaft (1)
02. remove the cam follower (2) and 12mm washer (3) Fig. 4-55
03. remove the cylinder gasket (1) and dowel pins (2) Fig. -S-57
4-5-3. Piston removal and inspection
01. remove the piston pin clip. Be sure put a towels under piston to prevent the clip drops (1) into the
crankcase. Fig. 4-56
02. clean any gasket material from cylinder surface Fig. 4-57
03. press the piston pin out of the piston and remove the piston
04. inspect the piston, piston pin, and piston rings
05. remove piston rings. Do not damage rings set Fig. 4-53
05. remove carbon deposits in the piston ring grooves.
06. install piston rings and measure ring to groove clearance.
* service limit TOP : 0.09mxn or more --- replace
2nd. : 0.09mm or more --- replace (Fig. 4-59)
07. remove the piston rings (1) and insert each piston ring into the cylinder bottom. And measure the ring
end gap. Fig. 4-60
* service limit: 0.05mm
08. measure the piston pin hole I.D. (a) Fig. 4-61
* service limit: 15.012mm
09. measure the piston pin O.D.(a) Fig. 4-62
* service limit: 14.96mm or less --- replace
10. measure the piston O.D. to take measurement at 10mm from the bottom and 90 degree to the piston pin
hole position. Fig. 4-63.
*
service limit; 61.8mm