Lights dragging down Idle.

Hi there. like the way the new site looks. Anyway finally have my 76 KZ400s running well enough to ride around town(just in time for the cold weather). For some reason when my lights (turn or brake) are on its dragging down my idle. What would cause this to happen? At least it runs. I'm going back out for another ride.

aproud1

aproud1 wrote:

Hi there. like the way the new site looks. Anyway finally have my 76 KZ400s running well enough to ride around town(just in time for the cold weather). For some reason when my lights (turn or brake) are on its dragging down my idle. What would cause this to happen? At least it runs. I'm going back out for another ride.

aproud1

I've always had this problem myself on my 750#1. And, while troubleshooting other stuff through the years, I have been reducing this problem.

I have found that on *my* bike, it's because of old, corroding wiring connections.

Every time I work with some connection, I cut and solder it, eliminating bullet connectors.

Next I'm going to do "the coil mod" that's so well known around here....

Not well known enough, apparently. Any info on the coil mod (what it is, why and how to do it, etc.)?

GargantuChet wrote:

Not well known enough, apparently. Any info on the coil mod (what it is, why and how to do it, etc.)?

All the answers to your questions lie in this document.

kzrider.com/component/option,com_docman/...ls/gid,106/Itemid,5/

The coil mod is a good idea if your noticing a decrease in idle when turning on your lights. I second Biquetoast's recommendation about the electrical system in general. On older bikes, the connections get corroded and don't conduct electricity as well. Using a wire brush and some contact cleaner to refresh the stock ones or just replacing them will likely improve your problem.

I'm pretty sure old corroding wire connections are all I have. I guess I see a new winter project coming along. Thnks for the info...

That sounds like a great idea. Maybe once I get my carb a bit more straightened out I'll try that. I only have a kick start so my right shin would appreciate a better spark.

I got a new battery and the difference was like night and day. I had to manualy switch my signals before the battery change, and my horn sounded like a hemmoroidal sheep fart. It all works fine now.