TOPIC:

I finally got my 78 kz650 running and was syncing my carbs (not as easy as it looks in writing). The person I bought the bike from had installed plug caps with little blue windows through which you can see the a light. While the motor was running I lost spark on cylinders 2 and 4 and I noticed the window on cylinder 4 was melted. At the very least I have to replace the caps. I am thinking more than likely I have to replace the coils as well. I have not opened the timing cover. If it is the coils, is there a substitute I can pick up at a local shop. Any thoughts would help.

I don't think it damaged the coils, replace the caps and see what happens.

Update it was 2 and 3 that went out. It didn't make sense for 2 and 4. If one cap burnt up, how come both cylinder went out? Also can I buy caps locally, like at a Kawasaki dealer?

ewolpert wrote: Update it was 2 and 3 that went out. It didn't make sense for 2 and 4. If one cap burnt up, how come both cylinder went out? Also can I buy caps locally, like at a Kawasaki dealer?

#2 and #3 spark plugs are part of the same secondary loop and are supposed to fire simultaneously as high tension voltage passes through the loop.





If the loop is broken for whatever reason, then the high tension voltage doesn't pass through either spark plug because high tension voltage isn't passing through the loop.





Good Fortune!

yep, two plugs form a series circuit so if you open either side, both plugs quit firing. 1-4 are a set and 2-3 are the other set.

So, do you guys think I can pick new caps up locally?

Depends on how big "local" is for you... since we don't know where you are located.

I don't know that it's just a cap issue, yet. Might have toasted the coils. But, this is a good place to start. Call around to some MC shops in your area and see if anyone can provide caps... If not, there are good online sites that can be suggested, on both sides of the pond.

Does the existing ignition coil have removable spark plug wires?
Or spark plug wires permanently built into the coil?

If the spark plug wires are readily removable from the coil, could simply replace them with a set of Dyna solid core plug wires from Z1 Enterprises.

The Dyna plug wires include integrated caps that attach directly onto the spark plugs, which makes it unnecessary to fit any other caps.

Good Fortune!

If your coils look like this, you can replace the leads.





I've never trusted those "sparkies" You might try your local small bike shop. They sometimes have a bone yard you can look through. If you can afford it, get some new ones.
Steve

If you can't get the sparkplug caps locally(try all of the Japanese motorcycle shops), www.z1enterprises.com has them.

www.z1enterprises.com/ItemDetails.aspx?i...LB05F&item=TU38-1001

www.z1enterprises.com/ItemDetails.aspx?i...VB05F&item=TU38-1009

www.z1enterprises.com/ItemDetails.aspx?i...SB05F&item=TU38-1005

The sparkplug wires are 14mm in size, and copper. Avoid getting the carbon fiber(resistive) as you could possibly have two resistances in the sparkplug ignition circuit, as the caps have a 5000 ohm resistor to reduce the "Snap" and "Pop" heard on Radio's and TV's, when sparkplugs fire.

Thanks all! I was able to pick up the caps at a local bike shop and the bike started up so no damage to the coils. Now I just have to figure out how to get my carb issues fixed.

Thanks again.