Re: Can I use this wire??
The THHN is the type of insulation. It is resistant to water, gasoline and oil so that's good. The MTW means it has extra flexible conductors (wire). 12 is big wire for your needs but will work just fine, especially if its free. You can go down to 14 and even 16 gage wire for the CDI primary circuit but if you already have that #12, like Cabin Fever says, "Go for it."
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