QuestionI bought the bike 8/1 with about 39,000 miles on it.
It ran fine until last month when it started giving me trouble. It would fire up, run for a few seconds, then die. Then, all it would do is crank and not start. I'd leave it alone, come back the next day, It would fire up, run for a few seconds, then die. Then, all it would do is crank and not start. Same thing happened over a period of a couple of week and then all it would do is crank and not start at all.
At first I thought it was a fuel problem but the carbs were overhauled Jan 07 (I have previous owner's records back to 1990).
I took apart the fuel petcock and it was fine.
So I moved on to ignition and here's where it gets interesting.
The spark plugs didn't look too bad but I replaced all four of them anyway. No help.
Held each plug to engine metal in turn and watch the spark. Very faint spark on each plug. Apparently not enough to ignite fuel.
I have the Clymer manual and ran the tests of the signal generator and ignitor per the manual (shaft drive).
The signal generator test requires an ohmmeter reading of between 250 and 360 to be good. Unfortunately, my ohmmeters are of questionable accuracy (cheap) but the digital meter read 360 and the analog meter read 400.
The ignitor test makes use of the battery voltage of the ohmmeter so I put in a new battery. When one lead is connected to the ignitor terminal, one grounded spark plug is supposed to fire. When both leads are connected the other grounded spark plug is supposed to fire. Both didn't.
Questions:
1 - Why would the plugs fire (at all) with cranking, but not during the ignitor test?
2 - Is it common for the signal generator and the ignitor to go out at the same time or just my bad luck?
3 - If I need to replace both the signal generator and the ignitor, do you recommend replacing both coils as a precaution since I've got everything apart anyway and they are old and cruddy looking?
AnswerWhat you describe indicates a dead battery or a lack of voltage to run the ignition system while the starter is operating.
What condition is the battery in? It's possible for the battery to have enough juice to run the starter but not enough to fire the ignition.
If you find the battery is dead then I would try charging it up again and try to find out if the charging system is faulty. It's common for the regulator/rectifier on these bikes to go.
Also, trim a little off the end of the ignition wires and screw the caps onto fresh metal. Also look for any corroded contacts between the battery and the coils. You might even want to put a tested multimeter on the coils and see what kind of voltage it is seeing on the wiring harness.
