Is My CDI Ruined?

GoldenMotor.com

Mercury

New Member
Jul 31, 2011
17
0
0
Austin, TX
I accidentally connected the CDI incorrectly. Black wire to blue. Blue wire to black. I tried starting my Grubee 66cc motorbike several times before I noticed my mistake. Is the CDI ruined?
 

Longshot270

New Member
May 8, 2012
112
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0
Texas
I don't think it would have fried it but that is a possibility. I noticed you're in Austin. Did you leave it outside during all this rain by any chance?
 

Mercury

New Member
Jul 31, 2011
17
0
0
Austin, TX
It's been inside. But it got pretty wet a few weeks ago. Noticed some rust at the top of the case. It did run yesterday. Then I took it off to replace the stock wire with the SB plug wire. Hasn't started since then.
 

Longshot270

New Member
May 8, 2012
112
0
0
Texas
The reason I asked about the rain is because I'm just south in San Marcos and don't have any kind of cover for the bike besides a hackberry tree. We got some really good rain and when I tried cranking the bike a few hours ago I was having a no spark on a bike that normally runs like a beast. I started loosening the magneto cover screws and got water streaming out. Blew it out with the air compressor and followed with WD40 and it ran for a short while. Then started to act like more water under the cover.

Edit: check that the boot is making a good connection with the plug. Normally when the bike doesn't start, go to the latest changes.
 
Last edited:

maurtis

New Member
Dec 14, 2011
707
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Kyle, TX
Mercury, I would definitely try rechecking your connections to the CDI and the plug wire and plug first, then check for spark by grounding your plug and checking for spark. Hopefully it was just a loose connection!

Longshot, I was just in San Marcos an hour ago, over at San Marcos Bearing Supply looking for a replacement needle bearing for the wrist pin. They did not have any :( If I can ever get my bike back together and find a back road from Kyle to San Marcos, we should hook up for a ride!
 

Mercury

New Member
Jul 31, 2011
17
0
0
Austin, TX
I believe my problem is due to a bad magneto. Per Al Fisherman's checklist, I measure resistance between blue and white wires. Measured 325 ohms, in line with 300-400 range. But the black and white wires had infinite reading. Same when I measured at the terminals within the magneto case. So large (black) coil must have a break in the wire?

Just ordered a new magneto from Dax. But then realized its a 6-hole magneto vs. my 4-hole magneto! Will it still fit and work?