PRESTOLITE OWNERS PLEASE READ!!!

[guitardude081]

For those that read my topic on my Uncle's '77 Liquifire, I just found the problem with my new CDI box. I ordered an SPI replacement (this is the Prestolite replacement you'll get from DK, Shade Tree etc.). The red and white coil wires WERE colored incorrectly, that is to say that they were backwards. I hooked them up as per the tech manual and all I got was a backfire. I reversed them (Red Wire MAG, White Wire PTO) and the sled fired on 1 pull and idled fine, took throttle fine and restarted after I hit the kill switch). I don't know that all aftermarket boxes are done this way but it's a good bet that they are. IF you get nothing but a backfire and all other ign. components, carbs and engine are good, try switching your coil leads.

Keep in mind that I had to splice the old round style connectors to this CDI box. The connector wire colors on the new one DO match up to the square style (style "B") and everything works when the round connectors are spliced in. This was only a headache that I suffered for about 30 minutes, and I hope this'll save a few people the guess work involved in a no-start situation with a new CDI. If you're in doubt on where to get a CDI, I'd say that Hewtech is the way to go because there is info in the FAQ section to prove that those ones are wired correctly.

Remember that if you have to splice the connectors, SOLDER them with quality electrical solder, don't use crimp connectors.
~Jack

[harleysportster]

Great info Jack!

[400brian]

The rebuilt CDIs that I have from Image were the same deal. I talked with Bob about it last October, and he indicated that it had happened in the past as well. Yup, the symptoms are backfire and no start.