No spark, 1991 TRX 300 FOURTRAX 2WD
Hello and thanks in advance for any help or resolutions,
I have a 1991 Honda fourtrax TRX300 2WD that was running fine until a couple of weekends ago. The battery has always seemed to hold a good 12.+ charge, I dont know how many amps it is putting off though.
I took the spark plug out to see if it fired/sparked. Nothing visible. But with the key on I could hear a faint ringing sound like when a TV is on but no picture just the black screen. The noise is coming from the larger of the two boxes under the front fender, the ICM/"CDI", ignition control module. when I turned the key off the noise stopped, until I turned the key back on and tried to start again, the noise returned. I then noticed when i touched the spark plug, in the plug wire still, to the engine some very small blue sparking occurred from the plug threads to the engine,none in the plug gap. would stop again with the key off. I measured the voltage coming from the plug wire itself when I kick start, it would jump up to around 6-7 volts then back down to almost nothing. I have cleaned about 5 plastic plug connections and the battery and solenoid terminals, with no resolve. A couple of funny things that happed while I was riding it the day before it died was that it simply went dead like you turned the key off while riding, not like it wasn't getting enough gas. It just went dead. I kick started it within one kick and it fired right up. Of course I would have these problems the day after I put a new brake cable on, new rear brakes, oil change, oil filter and air filter. But I don't believe this is the cause because it ran fine after doing all of these things. I Put in another CDI box that was supposed to be good. still no help. Now no current or voltage at all through the plug wires. But higher voltage from the CDI box through the wires that connect to the coil.
I replaced coil with a new one still no spark or voltage at plug wire, but there is still voltage through the wire that feeds the coil voltage. I have gotten the quad to start once but when it is killed no restart. What is happening? I have used the honda service manual and tried to test all the electrical as directed. the coil checks out OK, so does everything else seem to as well. But the little black diode has no "0" as indicated in the manual as it is supposed to have continuity, I jumped with a wire between the female connectors that the diode connects to. still no spark. but if the diode is bad would I still be getting voltage through coil supply wires? As I test the voltage between the green negative (black multimeter probe) and the Black and white wire Positive with the (red multimeter probe) I get a negative voltage like - 16.78 volts then it continues to drop as I let off the starter button. Is this correct? I have the batery positive and negative cables on correctly and the voltage at the battery is not inverterted as mentioned above at the coil feed wires. I keep the battery on a charger. Also would a bad battery stop the firing process cold even on a kick start attempt? If the diode was bad would i still get voltage at the coil supply wires?
Also I tested the pulse generator coil wire harnass and I checks out at the 348 or so Ohms as indicated in manual, but the manual doesnt specify where exactly to test it on which side of the connector, at the wires that go into the crankcase cover or on the other side going to rectifier? I get nothing going into crankcase wires and the 348 ohms on the other half of the connector going to the rectifier. Any suggestions?