Planet Minis

ynnek · 03-07-2008, 08:27 PM

I have a CT70 K0 that has secondary voltage coming from the coil, but will not fire a spark plug. All parts in the system are either new, or known good parts. (ign switch, coil, spark plug, etc.) So this seems like it may be some kind of ground problem, but I can't figure it out. Turning the bike over by hand, and holding a screwdriver in the spark plug cap sends a good zap to my hand, but grounding a spark plug to the engine produces no spark.

When holding the screwdriver in the spark plug cap, it actually zaps the hand cranking the kickstarter also. When cranking the kickstarter by the rubber pad and not touching any metal part of it, no secondary zap is felt at either hand. I have another running bike that I have swapped known good parts from trying to isolate the problem, yet still no spark at the plug. (jumper wire is installed at the battery connector) Any ideas?

FastMC · 03-08-2008, 12:19 AM

Start by eliminating the kill switch from the equation. You didnt mention anything about the points and condensor. Have these been replaced ? Are the contact surfaces clean and flat ? The source coil tests good ? If you replaced the points make sure you have all of the insulators in the right places where the points wire connects with the screw. It sound as if youre getting voltage but not the spike that should occur when the points seperate.

ynnek · 03-08-2008, 10:16 AM

The points and condenser are new. I just double checked the installation and everything is correct and secure. There is a good strong secondary jolt, but it only wants to jolt me, and not the plug. It acts just exactly as if the spark plug were bad, but I've tried 2 brand new, and 1 known good used spark plug.

ynnek · 03-12-2008, 07:47 PM

Quote:

Originally Posted by FastMC

The source coil tests good ?

You nailed it! Thanks!

03-07-2008, 08:27 PM	#1 (permalink)
ynnek PM Newbie Join Date: Dec 2007 Posts: 5	Tech question I have a CT70 K0 that has secondary voltage coming from the coil, but will not fire a spark plug. All parts in the system are either new, or known good parts. (ign switch, coil, spark plug, etc.) So this seems like it may be some kind of ground problem, but I can't figure it out. Turning the bike over by hand, and holding a screwdriver in the spark plug cap sends a good zap to my hand, but grounding a spark plug to the engine produces no spark. When holding the screwdriver in the spark plug cap, it actually zaps the hand cranking the kickstarter also. When cranking the kickstarter by the rubber pad and not touching any metal part of it, no secondary zap is felt at either hand. I have another running bike that I have swapped known good parts from trying to isolate the problem, yet still no spark at the plug. (jumper wire is installed at the battery connector) Any ideas?

03-08-2008, 12:19 AM	#2 (permalink)
FastMC Sporting the Merkin Join Date: Mar 2004 Location: boston area Posts: 5,072 My Mood:	Re: Tech question Start by eliminating the kill switch from the equation. You didnt mention anything about the points and condensor. Have these been replaced ? Are the contact surfaces clean and flat ? The source coil tests good ? If you replaced the points make sure you have all of the insulators in the right places where the points wire connects with the screw. It sound as if youre getting voltage but not the spike that should occur when the points seperate.

03-08-2008, 10:16 AM	#3 (permalink)
ynnek PM Newbie Join Date: Dec 2007 Posts: 5	Re: Tech question The points and condenser are new. I just double checked the installation and everything is correct and secure. There is a good strong secondary jolt, but it only wants to jolt me, and not the plug. It acts just exactly as if the spark plug were bad, but I've tried 2 brand new, and 1 known good used spark plug.

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