idle frustration!

Ok. here goes.
i just bought this bike and have been researching the heck out of things on this site and my manual. now im at my wits end and I would love some help.

The Bad news:
My main issue is a choppy idle. Other associated issues are poping from the carbs. Throttle racing up and down even when as normal operating temp. Sooty plugs after idling- i have not tested them at higher rpms.

The Good news:
The carbs are clean. No gunk and all the parts are moving. I have had them completley apart and have replaced any funky parts with stuff from a parts carb set. Bike runs great when on the road with lots of pick up and no smoke. So this leads me to believe it is only an issue at idle.

After reading many posts on this site here is what i have done:
1.Took apart carbs and checked all moving parts and seals and jets. bench synchroed.
2.New Petcock and inline fuel filter and clean new gas.
3.Set float bowl levels per manual technique. Made my own tube guage.
4. Flipped seals on bottom of Choke mechanisms (per wiredgeorge)
5. New ngk plugs 7es i think?
6. Removed, cleaned and lubricated automatic advance. also tried an extra i have.
7. replaced seals in side idle air screws, set them to optimal idle setting between 1.5 and 2 full turns.
8. lubed throttle cables and ruled out faulty return spring on carbs.
9. Synchronised carbs and checked compression- throttle open. Compresson not bad but not great. 155,145,155,162.
10. sprayed wd40 on carb boots while running. no change in idle and vaccum ports are capped.

Things i have not done and why:
1. not checked timing--why. because i dont have a timing gun and it runs fine when not idling.
2. have not tested ohms for ignition system stuff because i didnt think that was the issue.
3. Have not adjusted points-again because it runs fine when not idling and they look clean.

Sorry for all the info but it seems like it would help. So does anyone believe this is still a carb issue? The sooty plugs counter act my thought that the carb popping is due to a lean mixture at idle. I really need to find a set of clean carbs from a strong running 650 to swap on to rule this out. Thanks for any suggestions.

Post edited by: 70seven6fifty, at: 2006/02/02 19:35

Welcome to KZR.

Are your pods clean and oiled?

You may need a jet change on the pilot jets? Did you swap the pods on without a jetting change or were the carbs rejetted?

Gives us a pic of your 70seven6fifty as well.

It would be a really good idea to buy/borrow a timing light and set the timing as it can cause the symptoms you are describing. It may very well run fine, but if the timing is retarded (and that's what it sounds like) it will run even better when the timing is set correctly.

My son thought his 650 was fast until I set the timing, then he thought it was really fast

Try doing the "coil powering- direct from battery" mod, its in the filebase in the non-modle specific section, written by carb king wiredgeorge.
Scott

thanks for the info. i will try the timing adjustment and the coil rewiring. they seem like good things to do regardless.

I have not oiled the pods. What does that do? Its seems like i should wait to rejet until i rule out some of the ignition things? Does that make sense?
thanks for the help.

The sooty plug issue is likely a weak spark and doing a coil wiring mod will help. I wouldn't play with the carburetors anymore till I adjusted ignition timing and the valves clearances (if you haven't done so). As far as the erratic idle, that is indeed a carburetor problem and not related to valves or the ignition timing. Have a look at the link in my signature.

I second sorting out the electrical side of things.
My bike wouldn't idle smoothly, was not really responsive to the idle mix screws, was cranky off idle and when trying to move from a standing start etc. Also used to backfire etc through carbs.
Once I replaced teh coils and fitted the electronic ignition, I had a smooth idling bike that is very tractible and forgiving off a standing start.
I also found that the wiring from teh points had chafed through at the point it exits the engine case and was shorting to earth at random occasions (like at intersections!!!)

Regards, Andrew.

My 81 KZ-1000 had a hard time dropping to idle when I stopped at lights. It ran great at 1/4 throttle and above. I finaly determined that the carb boots had cracks where they attached to the cylinder head. I had to pull them off to find this. the solution was to replace them and use Non Hardening Permitex (Aviation Grade) Gasket Sealer.

Make sure that the mounting screws for the boots have clean threads or you can have a temprary seal that changes to a leak as you test drive it. If you ride it with a noticable air leak from the boots you can easily burn a piston.

Do not use silicone sealer because the gasoline in the air/fuel mixture will degrade it quickly.

Hope this helps,
Spock

poor idling is "generally" caused by a carb condition. whether it be intake boots (engine side} are cracked. or a mixture screw setting being maladjusted. but even though you say you cleaned the carbs, sounds like a pilot jet{s} being obstructed.

If you're looking to "try" the coil mod, you can pull the yellow wires coming from the coils out of the 2-to-1 female connector, and use a spare piece of wire to jump them (the two yellow wires, one from each coil) straight to the battery positive terminal.

Cons:

• It's like leaving the key on, so you'll drain your battery if you leave the wire connected!
• You'll have to manually disconnect this wire in order to shut the bike off. Watch for sparks!

Pro:

• It's a quick, cheap, and easy way to see whether it's worth the time and money to do the relay setup properly.

I actually tried this late last week, and it did make a fair difference in acceleration on my stock 650, as well as giving a smoother idle. I plan on doing the coil power modification, but I can't bring myself to cut into the stock wiring, so I'm going to wait and get some good terminal connectors and make a plug-in harness so that I can remove the relay if needed in the future.

Again, it's the two yellow wires, one from each coil, and use a piece of wire to jumper them straight to the POSITIVE battery terminal. Be sure to wrap it all in electrical tape to avoid shorts.

But don't run your bike like this for more than just a test run, because it's effectively bypassing your kill switch and even the key. You can hit the kill switch, take out the key, and the bike will continue running until you remove the wire from the battery. It's okay for a test, but not a permanent solution!

That sounds like a good test. ill give it a shot. thanks Gargantuchet

On my 98 KZ1000 would that be the red wires instead of yellow?