1985-1986 Honda Fourtrax 125 TRX125 Shop Manual, Page 32Get this manual
MAINTENANCE
CYLINDER COMPRESSION
Warm up the engine Stop the engine and remove the spark plugInsert compression gaugeMake sure the choke is full closed, and the engine stop switch "OFF "Fully open the throttle and turn the ignition
switchON "Push the starter button unti the compression gauge reading stops risingNOTE
Watch for compression leaks at the gauge con
nection
COMPRESSION :
STANDARD: 12.5 1.5 kg em' 1177.8 21 .3 psi) SERVICE LIMIT9.0 kg e m' (128.0 psi)
BATTERY COVER
WING BOLT
Low compression can be caused by :
Improper valve adjustment