OK fellows I posted a thread on here awhile ago about a 1979 XS650 pouring gas out the one carb. The general consensus was to re-build the carbs. OK did that. Also split the fuel lines and am running one fuel line from one petcock with 1/4" I.D. line. New problem. The bike won't start. Spray starting fluid into the cylinders and turn it over and nothing. Not a putt. Bought new plugs and still nothing. Hold the plugs against the cylinder header and turn it over and, well, really I can get more spark by skipping stones off the road. Can anyone tell me if these 650's just don't make the kind of spark you get from automotive plugs or V twin plugs or are they good firing electrically and I just have another problem. Spark also seems to be intermittent on the left side, but I see that's a common problem on here.
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Very weak spark.
- Thread starter OldGuy
- Start date
bloodthirstysystem
XS650 Addict
if everything works you get a big fat blue spark. take an old plug and bend the electrode (?) straight out. it should be about 10mm long when jumping across to the engine..
1. file the points so they're not pitted, clean them with lacquer thinner, set the gap, try spark again.
2. test coil resistance, clean all electrical contacts in the ignition system
3. replace condenser
1. file the points so they're not pitted, clean them with lacquer thinner, set the gap, try spark again.
2. test coil resistance, clean all electrical contacts in the ignition system
3. replace condenser
Yup it should show a healthy spark, you have issues. Standard tune up and spark troubleshooting will have you back to fat blue and healthy. Suspect and test EVERYTHING assume nothing is functional that will spare you a day or two of hair pulling.
I just got done with trying to fix a Kawasaki 305 that looked like it had healthy spark but would NOT hot start. After way too much run around, I installed a relay to remove many feet of substandard wiring and switches from the coil feeds, she starts instantly hot or cold now.
I just got done with trying to fix a Kawasaki 305 that looked like it had healthy spark but would NOT hot start. After way too much run around, I installed a relay to remove many feet of substandard wiring and switches from the coil feeds, she starts instantly hot or cold now.
PhatTony
I love twins
I had similar problems with my bike. Intermitent spark on the right side. Turned out to be a wire from the right side points shorted. Bought a Pamco and never looked back. Fat Blue spark on both plugs all the time.
I also did the ignition coil relay mod as well. This mod allows you to run a line direct from the battery through a relay and you get 12+ volts to the coil with the ignition on. Amazing that after 30 years of corosion and the wiring and switches can't carry 12 volts sometimes. Use the original wire coming from the stop switch to trigger the relay. I read about it when I had a KZ1000 and have done it on every bike I own since. Just an idea.
I also did the ignition coil relay mod as well. This mod allows you to run a line direct from the battery through a relay and you get 12+ volts to the coil with the ignition on. Amazing that after 30 years of corosion and the wiring and switches can't carry 12 volts sometimes. Use the original wire coming from the stop switch to trigger the relay. I read about it when I had a KZ1000 and have done it on every bike I own since. Just an idea.
Thanks for the suggestions, but I have a few questions for you. Number one being can I clean the points in place, or do I have to remove them? And if I have to remove them, how do I get them out? And what gap should they be set at? And where is the condenser located? I read above the top motor mount, but its not there. The only think I can find that resembles a condenser is right above the coils, but it looks nothing like the ones that mikesxs sells. Sorry for the stupid questions, but I'm new to these Yamahas. Thanks.
bloodthirstysystem
XS650 Addict
don't remove them. open them up with your finger to see if they're worn out. if so hit them with a file or sand paper. to clean them use some card stock or heavy paper, soak in lacquer thinner . open the points with your hand, put the wet paper i there and work in around until the grey shit stops coming off. i do it a few times with different pieces of paper.
points should be gapped between .012 - .016". sometimes a larger or smaller gap will prevent you from adjusting timing fully. you will have to play around with it and it can be a pain in the ass.
condensers are between the two top motor mounts unless someone moved them
points should be gapped between .012 - .016". sometimes a larger or smaller gap will prevent you from adjusting timing fully. you will have to play around with it and it can be a pain in the ass.
condensers are between the two top motor mounts unless someone moved them
Are there any differences between symptoms of a bad coil or a bad condenser? I have a feeling I'm going to have to replace one or the other. I see everybody talking about their spark, mine can't even be called spark compared to what I'm reading from other people. Its more like little flashes of orange every once in a while.
If you still have the original 31 year old coils, I would throw them away and buy a new dual output coil. The original coils had only 10 k to 13 k voltage................add in some corrosion (maybe kill switch has high resistance) on your wiring connectors = poor spark.
Keep in mind that points ignition need a coil with about 4.5 ohms primary...................you can't use coils with 2.5 to 3.5 ohms.
Those old original fuse panels (glass fuses with clips) are bad news and will rob you of voltage. Replace with automotive blade fuses.
Better yet, buy a Pamcopete kit with a good coil.
Keep in mind that points ignition need a coil with about 4.5 ohms primary...................you can't use coils with 2.5 to 3.5 ohms.
Those old original fuse panels (glass fuses with clips) are bad news and will rob you of voltage. Replace with automotive blade fuses.
Better yet, buy a Pamcopete kit with a good coil.
bloodthirstysystem
XS650 Addict
after rebuilding the motor last winter one side wasn't firing - no spark. i cleaned the points and it worked.
after a few weeks of riding both plugs got weak - replaced condensers and they are now fat blue sparks. original coils but i should replace them. if anything gives me problems again i'm going with the pamco and do away with points and condensers
read this, cheap condenser replacements from pamcopete
http://www.xs650.com/forum/showthread.php?t=1743
and i even went with cheaper condensers from a 1960's ford f100 pickup. about $5 each
after a few weeks of riding both plugs got weak - replaced condensers and they are now fat blue sparks. original coils but i should replace them. if anything gives me problems again i'm going with the pamco and do away with points and condensers
read this, cheap condenser replacements from pamcopete
http://www.xs650.com/forum/showthread.php?t=1743
and i even went with cheaper condensers from a 1960's ford f100 pickup. about $5 each
Thanks for the info, but how did you wire them up. And how did you mount them? Do they come with alluminum mount I can just bend up and rig in there somehow?
