Post by havinapretzel on May 14, 2011 0:57:24 GMT -6
Hi everyone, I have an '86 454 LTD which has developed an odd problem. I've been working on this bike for about 14 months on and off, and thought it was ready to ride until this happened. BTW, none of the problems I've had to address so far have been electrical (until now).
This bike has always had a spark, except for when the starter clutch was going bad. I replaced that last weekend, and have since developed this problem: sometimes I have spark, sometimes I don't. After I put the alternator cover back on (and cleaned the carbs a few days later because some old gas was still in them) the bike started right up and ran for a minute or so and died. It wouldn't restart, so I tested for spark and didn't get any on either cylinder (I test for spark by grounding the plugs to the cylinder head and hit the starter button for a second; I just learned about inline spark testers and will buy one tomorrow). I pulled the pulley cover back off and wiggled the wires that come out of the alternator cover and got spark again.
That was last night; I figured the problem was fixed and that today I'd be able to start her up, make sure my oil & coolant levels were good, adjust my cables and go riding. This wasn't so; I was able to start the bike this evening, but it idled at about 2500-3000rpm and died while I was adjusting the idler screw. It wouldn't restart, so I checked for spark again and had none. I tried wiggling those wires again, but had no luck so I pulled the alternator cover back off. Everything looks fine; the magnets aren't rusty or anything; all the wires are intact, including the external ones. The only thing I saw that might have to do with this is a dent in the insulation of one of the wires that exits the alternator cover and runs between the crankcase/gearbox and the pulley cover, but judging by how it looks I think that dent's been there for awhile. I put the cover back on and had spark when it was still a little loose, but lost it after I tightened the bolts (not crazy tight, just tightened a little beyond when I start feeling resistance).
I tried taking the cover on & off a few more times, wiggling wires, etc but still couldn't get spark back. Then I recalled that the manual says to disconnect the negative lead from the battery; I did this when I replaced the starter clutch but forgot to do so the other times I pulled the cover off. This time I disconnected the negative lead, pulled off the cover, looked inside again (everything still fine), put the cover back on and reconnected the negative lead. The bike started right up and idled fast like before; I turned down the idler screw but the revs crept back up so I cut it off, grabbed the little screwdriver i use to adjust the idle mixture, adjusted the crews a quarter turn, and tried to restart the bike. It wouldn't fire, so I tested for spark agan and got nothing. Then I noticed it was almost 2am so I decided to stop for the night.
What do you think is going on here? I'm pretty good with mechanical stuff, but electrical knowledge is a weak point for me. I'd appreciate any advice you can give me.
Here's some other info, which may or may not be relevant to this issue:
-plugs are relatively new and properly gapped;
-battery is several months old and fully charged;
-I have two sets of working coils for this bike; I switched them out and had the same problem;
-carbs are clean, air filters are almost new, valves are properly adjusted;
-all 3 fuses are intact.
This bike has always had a spark, except for when the starter clutch was going bad. I replaced that last weekend, and have since developed this problem: sometimes I have spark, sometimes I don't. After I put the alternator cover back on (and cleaned the carbs a few days later because some old gas was still in them) the bike started right up and ran for a minute or so and died. It wouldn't restart, so I tested for spark and didn't get any on either cylinder (I test for spark by grounding the plugs to the cylinder head and hit the starter button for a second; I just learned about inline spark testers and will buy one tomorrow). I pulled the pulley cover back off and wiggled the wires that come out of the alternator cover and got spark again.
That was last night; I figured the problem was fixed and that today I'd be able to start her up, make sure my oil & coolant levels were good, adjust my cables and go riding. This wasn't so; I was able to start the bike this evening, but it idled at about 2500-3000rpm and died while I was adjusting the idler screw. It wouldn't restart, so I checked for spark again and had none. I tried wiggling those wires again, but had no luck so I pulled the alternator cover back off. Everything looks fine; the magnets aren't rusty or anything; all the wires are intact, including the external ones. The only thing I saw that might have to do with this is a dent in the insulation of one of the wires that exits the alternator cover and runs between the crankcase/gearbox and the pulley cover, but judging by how it looks I think that dent's been there for awhile. I put the cover back on and had spark when it was still a little loose, but lost it after I tightened the bolts (not crazy tight, just tightened a little beyond when I start feeling resistance).
I tried taking the cover on & off a few more times, wiggling wires, etc but still couldn't get spark back. Then I recalled that the manual says to disconnect the negative lead from the battery; I did this when I replaced the starter clutch but forgot to do so the other times I pulled the cover off. This time I disconnected the negative lead, pulled off the cover, looked inside again (everything still fine), put the cover back on and reconnected the negative lead. The bike started right up and idled fast like before; I turned down the idler screw but the revs crept back up so I cut it off, grabbed the little screwdriver i use to adjust the idle mixture, adjusted the crews a quarter turn, and tried to restart the bike. It wouldn't fire, so I tested for spark agan and got nothing. Then I noticed it was almost 2am so I decided to stop for the night.
What do you think is going on here? I'm pretty good with mechanical stuff, but electrical knowledge is a weak point for me. I'd appreciate any advice you can give me.
Here's some other info, which may or may not be relevant to this issue:
-plugs are relatively new and properly gapped;
-battery is several months old and fully charged;
-I have two sets of working coils for this bike; I switched them out and had the same problem;
-carbs are clean, air filters are almost new, valves are properly adjusted;
-all 3 fuses are intact.
