No Spark By tankrider (Read 810 times)

[tankrider]

OK here's the issue: As I posted in a 'previous forum' I had to rebuild the engine on my Tank. Broke it in nice and slow this time. When I finally got to the point that I could go full throttle that's when issues start. At anything much over 5000 rpms it would sputter, miss, backfire, die but start right back up. Figured I had fuel or carburation issues. Cleaned the carb, replaced fuel filter this morning went to start it and no dice. Found that I have absolutely no spark. Bad coil?

[JR]

Could be but since it's starting to sputter and such first I woulds check all the wiring connections especially the coil wires both the yellow/black and the ground, even a bad ground will cause this.

The black/yellow wire from the CDI goes to the coil and it's been known to lose connection especially the Chinese spade connectors.

Lets eliminate any no cost issues before we start throwing parts at it. Also the I believe if I'm correct red/black from the stator to the CDI needs a good connection to get it's power.

Let us know and get back.

JR

[sprocket]

From what you describe it is the CDI. The capacitors in these get weak and don't fully charge, or more often they fail to fire at a high RPM. So if it is sputter at 5000rpm I would look at the CDI. But it could also be the pulse coil... they can fail at high RPM as well...

Ignition coils usually work or they short or open.. they rarely go intermittent...

Need to run some diagnostics

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[tankrider]

Started digging around in my 60 year old brain and remembered some voltage readings I read on one of the first forums I joined six years ago. Put my meter leads across the two wires going to the coil and hit the starter. I was only getting 2.85 volts. Replaced the stator of which I actually had a spare and it started on the first crank. Been giving it a final test ride for the last couple of hours before I start riding to work again next week.

[JR]

Great! Now if I can just get those tech diagnostics in! LOL Glad you got her going!

JR