Ok, I've posted on Yahoo Answers about this problem before. Here's my original question:
1980 Honda cb650 Custom keeps dying on the road. It initially starts out fine, but after traveling in 3rd or 4th gear for a while, I notice that it's not responding as much when I roll on the throttle. Then, when I try to take it up hills, the rpms just drop, like I'm not giving it any gas at all, and it just shuts down. Each time I get it started, it gets harder and harder to start until it won't even push-start. When it comes to an idle at a stop, even if I keep revving it, it'll shut off. It died on me like this about a month ago and I took it to a Ducati shop to be serviced (there are no Honda shops in my area). They said it was the carbs and completely cleaned them, timed, and serviced them. They even put a little fuel filter on the main fuel line. But I just test-drove it again today, and after about 10 minutes of riding, it happened again and I had to push it home. I thought it might be the battery, but I just checked it with a voltmeter, and it's fine. Other things I have done to this bike: replaced air filter, fuel tank, petcock, fuel line, tires, battery, adjusted and bled brakes, and had the carbs professionally cleaned. It's still not working! Help! Why does my bike keep breaking down like this??
And, the original answer:
Bad coil.
When they heat up, the internal windings expand and separate.
When the coil cools down, the wires contract and reattach themselves.
Keep a known working spark plug with you.
When the engine dies, immediately check for spark.
Pull off a spark plug cap - insert the good spark plug - lay the threads of the plug against the engine and try to start the bike.
Check all 4 spark plug caps.
If a spark plug won't spark, get the coils checked.
And check the spark units (common problem with Hondas of that era).
While that answer was well-reasoned and completely logical, there is still a problem. The bike has two ignition coils, each powering two spark plugs. I tried starting the bike this morning, but it wouldn't even push-start. I have tested each spark plug cap with a brand new spark plug, and barely got a spark in any of them. This means that A) BOTH ignition coils are bad, which is unlikely, or B) something else is wrong.
I was thinking that it might be the alternator, because the battery (which I charged last night before testing the coils this morning) gets drained pretty quickly, even when I'm not riding the bike. Would a bad alternator cause a starting problem? What about the stator or spark units? I've read the manual, and it recommends to have pros inspect both the spark unit and the alternator, because you risk f'ing it up real bad. Please help! Thanks in advance!
1980 Honda cb650 Custom keeps dying on the road. It initially starts out fine, but after traveling in 3rd or 4th gear for a while, I notice that it's not responding as much when I roll on the throttle. Then, when I try to take it up hills, the rpms just drop, like I'm not giving it any gas at all, and it just shuts down. Each time I get it started, it gets harder and harder to start until it won't even push-start. When it comes to an idle at a stop, even if I keep revving it, it'll shut off. It died on me like this about a month ago and I took it to a Ducati shop to be serviced (there are no Honda shops in my area). They said it was the carbs and completely cleaned them, timed, and serviced them. They even put a little fuel filter on the main fuel line. But I just test-drove it again today, and after about 10 minutes of riding, it happened again and I had to push it home. I thought it might be the battery, but I just checked it with a voltmeter, and it's fine. Other things I have done to this bike: replaced air filter, fuel tank, petcock, fuel line, tires, battery, adjusted and bled brakes, and had the carbs professionally cleaned. It's still not working! Help! Why does my bike keep breaking down like this??
And, the original answer:
Bad coil.
When they heat up, the internal windings expand and separate.
When the coil cools down, the wires contract and reattach themselves.
Keep a known working spark plug with you.
When the engine dies, immediately check for spark.
Pull off a spark plug cap - insert the good spark plug - lay the threads of the plug against the engine and try to start the bike.
Check all 4 spark plug caps.
If a spark plug won't spark, get the coils checked.
And check the spark units (common problem with Hondas of that era).
While that answer was well-reasoned and completely logical, there is still a problem. The bike has two ignition coils, each powering two spark plugs. I tried starting the bike this morning, but it wouldn't even push-start. I have tested each spark plug cap with a brand new spark plug, and barely got a spark in any of them. This means that A) BOTH ignition coils are bad, which is unlikely, or B) something else is wrong.
I was thinking that it might be the alternator, because the battery (which I charged last night before testing the coils this morning) gets drained pretty quickly, even when I'm not riding the bike. Would a bad alternator cause a starting problem? What about the stator or spark units? I've read the manual, and it recommends to have pros inspect both the spark unit and the alternator, because you risk f'ing it up real bad. Please help! Thanks in advance!