Honda CR125R 1992 User Manual

16. Technical Feature
H.P. P. (Honda Power Port)
The H.P.P. !Honda Power Port) in designed to broaden the engine's power band without sacrificing peak power .
It
does this by automati cally varying the height of the cyl iflder 's exhaust port. The exhaust port timing changes as engine
speed increase
or decrease; so that the engine can produce its best possible power output at any given engine speed.
At low engine speed, the exhaust valves are closed tor mild exhaust port tim ing. As the en gi ne speed increases , the exhaust
valves begin to open to give maximum efficiency . At high engine speeds, the exhaust valves ar e fully open .
(12} PINION GEAR
11) VALVE GUIDE LOCK BOLT
( 10 ) PINION
GEAR
RICE RED
(2) EXHAUST VALVE
I I I I I
(4 ) EXHAUST VALVE LEVER
(5)
PINION HOLDER
(8) DRIVE SHAFT LEVER
(9)
VALVE ROD
16-1

Honda CR125R 1992 Specifications

General

Bore x Stroke	54.0mm x 54.5mm
Compression Ratio	8.5:1
Transmission	5-speed
Front Brake	Single disc
Rear Brake	Single disc
Front Tire	80/100-21
Rear Tire	100/90-19
Ignition	CDI
Engine Type	Liquid-cooled, single-cylinder, two-stroke
Rear Suspension	Showa, Pro-Link, adjustable compression and rebound damping