Q: With a cold engine it doesn’t respond to quick throttle openings. There is a bit of a difference once the engine is warm-though from about 55mph upwards, when the throttle is open to accelerate, the bike starts to chug and miss. If the throttle is held open to hold speed to 55-60 after about two miles the engine smooths out. The bike will go up to 70mph, using gentle throttle, when joining a motorway, but will not take heavy acceleration. I wired a switch into the diagnosis plug and when the fuel injection light came on the codes 24 and 25 came up. The light resets after ignition is turned off and restarted, when the diagnosis switched on with engine off it shows -c00(no code.) The throttle position is correct, I have carried out an ohms test on ignition coils and crank shaft sensor and all are correct.
A: The C24 and C25 codes are errors within the ignition system. The ECM has detected that no signal was received from the ignition coil for (what it regards as) an extended period i.e. 0.5 seconds. This is generally caused by a poor electrical supply to the system (perhaps because the battery voltage is low or the battery itself is unserviceable) or a bad electrical contact in a wiring connector, or possibly a faulty ignition coil.Enjoy more Classic Motorcycle Mechanics reading in the monthly magazine. Click here to subscribe.