So let me tell you a story.....
I pushed home a dead ‘98 my neighbor gave me. Less than 13,000 miles. It hasn’t run in maybe 2 years. I’ll try to keep this short.
Original owner is now 80. I actually shared an office with him when we both worked and can remember when he bought it new.
A few years ago he decided to sell it and took it to a Honda dealer to “tune up” or do something to something in preparation for sale. He had quit riding by this time and would only start the bike and let it run to keep it in good shape. He stored his bike in his entryway. He started the bike and let it idle and walked away, he completely forgot about. When he found it it was dead. Rolled it in his garage and covered it up.
I got it home. Dead battery replaced with new battery. Checked oil. Looked good. Checked coolant. Had to add about 1 quart. Gas tank completely dry. Added fuel. Fuel leaked out everywhere. Shoved drain pan under bike. Lifted rear of tank and learned about the shutoff valve. Vacuum petcock leaked and fuel was coming out the carb overflows.
Ordered rebuild kit for petcock and completed that. While I was waiting for parts I rigged up a fuel supply and tried to start the bike. I pinched shut the vacuum line to the fuel petcock. Bike wouldn’t start but would fire. Overflows in carbs quit leaking gas.
Procured starting fluid and removed air-box cover. Gave each carb intake a squirt and bike started. Ran very poorly.
After the bike warmed a bit I could keep it running at about 3-4000 rpm. Even lower but obvious miss and wouldn’t idle. I independently squirted starter fluid into each carb inlet. I got an obvious and strong response in revs except cylinder #3. #3 was dead. No response for #3.
After running the bike a took exhaust header temps using a laser temp gun. #3 was twice as hot as the other 3 cylinders. About 350 ish vs 175 ish F.
Pulled plug #3. Looked good. Hooked up to coil could see spark.
Out with all the plugs and completed compression test..... all 4 cylinders even at about 135. Throttle wide open and holding the vacuum slides open with a finger.
Put new plugs in. Put bike back together with fuel tank on properly.... same thing. Bike runs crappy. Misses. Exhaust header 3 temperature way hotter and out of family with other temps.
The bike fires for plug #2 and #3 at the same time. I believe the spark I was seeing was for the number 2 power stroke and not the #3 power stroke. I believe the spark occurring for #3 is at the exhaust stroke and is burning the fuel in the exhaust system explaining the high header temperature.
Soooo.... my question is what initiates and controls the ignition spark for cylinder #3 power stroke? I’m suspecting a crankcase or camshaft position sensor, both or ignition timing module or something.
I don’t have a manual yet and am not sure if this bike has these sensors and where they are.
Any my thoughts on my next move?