burn out
- Thread starter grizadams
- Start date
Sanding the coils in the engine is a bad idea. The lacquer is there to insulate the wires in the coil. Best left untouched unless there is trouble. Do you still have spark? Is the coil sending power to the cdi? Seems like a lot of people have problems with the coil wire. (from the cdi to the plug)
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Of coarse you should never sand the coil wire in a magneto, but you SHOULD sand the lacquer from the bottom side if the metal core where it bolts up to the crankcase, so it gets a good ground connection...
What is the problem you are experiencing? Running the wrong plug could cause you a problem, so why not run the right plug? Try an NGK BP6HS plug, lots of us are running them and they work great..
Edit: by "cause you a problem" I mean the motor may not run properly with the wrong plug.
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the plug shouldn't burn out a CDI. more likely, it's a bad connection somewhere, crappy plug wire, or shorting out at your wires. i'd go through your wiring, make sure the kill switch is wired up correctly (if you're running one,) solder all the wires instead of crimping them, and make sure nothing's grounding out that shouldn't be.
or, it could just be a defective batch.
or, it could just be a defective batch.
Yes, CDI's have been known to fail, mine never have, but I have read about it enough in the forum... I can't confirm the cause of failure for others, I suspect it would be a bad solder connection inside the sealed CDI box. I run an automotive wire in my CDI, so far so good with about 1,500 miles on it. It could also be the crappy plug wire that fails on the cdi....
It apparently means your new CDI is measuring 2.5K Ohm from black wire to plug wire, but your used/failed CDI has gone up to 6.8k Ohm. This could be due to increased resistance in the plug wire or something inside the box. I haven't really dug into CDI design (yet) others have and are building their own, so they might have more to add....
One thing for sure, the stock plug wire and boot on the CDI sucks....
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Did you disconnect the kill switch to make sure its not a problem, and make sure you isolate the white wire, check the connections between the CDI and magneto? Re soldering the magneto sometimes does the trick (when you have a poor connection to the core). Have you read this page yet?
http://www.grubeeinc.com/USA/Magneto Mystery.html
Pretty much, make sure the outer diameter of the wire is the same as the one in your cdi... I will paste in below from an older post I made about upgrading my plug wire....
Where the plug wire goes into the CDI the wire simply screws down onto a wood screw, that makes the electrical connection and "kinda" holds the wire in place, no joke! The wire is also glued in there, some say very lightly but mine was glued in there pretty good.
Twist the wire as if you are threading it off of a screw, you will probably need to use some pliers, and if yours is as glued as mine the wire will probably break off pretty much at the base. I took some small tools, exacto knife, pointy nail etc and slowly picked out all that rubber from the old wire working from the center to the outer edge. Eventually you will see the tip of a wood screw emerge. Clean it out until the screw is visible and the hole is clean enough to thread a new wire in there.
Go to your local auto parts store and ask them to look at their single spark plug wires. I picked one that was two foot long and had a spark plug boot on both ends (it said it was a coil wire), cut it in half and had a plug wire and boot for two CDI's for $4 bucks!
Whatever wire you choose, prepare a nice straight cut on the end, apply some silicone sealer around the outside of the wire and thread it down onto the screw in the cdi. Apply some extra thick silicone around the outside of the wire where it mates to the CDI and let dry, your done... Now you got a REAL spark plug wire!!!
PS you will need to screw that cap back on your spark plug with the new wire.....
All I know is my bike was running like a champ and I'm flying along and it just dies and I got no spark. And then today I get a new cdi, I install it and I got spark so I button it up, jump on it and try and start it and nothing, so I check the spark and it's gone. I understand the wiring on this thing, I had it running for a couple of weeks before this weird stuff started happening. I've re soldered all of the connections in case I had some cold connections and it's all taped of so it won't short out. My old cdi's readings seemed wrong and my magneto readings seem spot on. That's why I got a knew one.
Well, perhaps you might re-evaluate where you are mounting the CDI? It seems odd to go through so many, perhaps the CDI is getting vibrated excessively where it is mounted now? Just a thought.....
I'm pretty sure I said this in my post earlier....
Stop by the desk at the autoparts store, ask them to see their SINGLE WIRES, they usually have a box behind the counter. My local auto parts store had a box of a bout 50 different single wires. I sorted through them myself until I found one with the type of ends I wanted. I think it was a coil wire, it had a small right angle boot on both ends, I cut it in half and had a wire for two CDI's. I didn't mean to indicate that your need to buy a complete set of wires for a car....
