1985 nb50m has weak spark

[tricolour]

Wondering why my scooter would not start, I checked the spark. It's very thin and weak, even with a NEW spark plug. What would cause this? I would expect with electronic ignition, it would either work great or not work at all. Is there a common part that fails when this happens? What about possible faulty grounds?

[Bear45-70]

Testing of all the ignition components is covered in the service manual.

[bc117]

in my experience it is gonna be the coil and you can buy those off ebay for like 15-20 dollars from gy6 scooters, i just did this recently and the coil works flawlessly. heres some links as you can see old broken honda coils are like 36 dollars when you can buy two brand new coils for that price

http://cgi.ebay.com/HIGH-PERFORMANCE-SC ... 3a5c9958a6

http://cgi.ebay.com/ebaymotors/Ignition ... ccessories

http://cgi.ebay.com/ebaymotors/85-HONDA ... leQ5fParts

[Bear45-70]

Never buy aftermarket ignition parts. They are not as good as the Honda parts. Oh and the spark plug is 10 times more likely the issue than the coil. Oh and used ignition parts is asking for trouble.

Also, always troubleshoot the problem before you start throwing parts at it.

[bc117]

ya but he got a new plug and the problem persisted

[Wheelman-111]

Greetings:

A "weak" spark in daylight turns into a SuperNova in the dark. If you can see spark at all, I doubt that spark is the problem. I had to re-fire Ms. Wheelperson's Sportster this weekend, hunting down a no-start problem. I checked the spark plug - faint, barely visible flicker found, even in the dark Garage.

Anyway, evidently goof-prone Wheelman had neglected to set the manual petcock to Flow. After that, started and ran fine with its "weak" spark. If you haven't tested the ignition output with an oscilloscope, we may have reached a "conclusion" that is invalid.

I recommend you follow ALL the checklist procedures - Compression, Fuel, Timing - before you embark on purchases that may not solve the issue.