TOPIC:

So I have read several things all over the web as well as on here about my issue. I have tried several things but to no avail really. So I put a dyno jet stage 3 kit in my 1981 kz550ltd. I have synced the carbs and did all adjustments per their specs. They all read the same on the sync gauges and choke and cable operation is all perfect. When the engine is cold I have to crack the throttle open to start it and hold it cracked open for a couple minutes then it has a very low idle for about 10 minutes till it warms up. Once its warm it runs perfect and starts right back up! What am I missing?? Any help would be greeeeeatly appreciated!!!

Thanks
Tyler

Are you using the choke? Have you checked the choke flaps?

The manual show where to adjust the "fast idle" which is the warm-up idle speed. When you apply the choke, the throttle is automatically held open a bit. The amount can be adjusted. But you have to make sure all of the other parts of the choke operation are working before you make adjustments.

Here is a link for checking the choke flaps;
s3.amazonaws.com/gpzweb/TK22mainPage/TK2...chokePlateFlaps.html

Here is a link for a very easy modification you can make to the fast-idle adjustment so you can adjust it without taking the tank off.
s3.amazonaws.com/gpzweb/TK22mainPage/TK2...astIdleScrewMod.html

ALRIGHTY!!! Thanks man. I have not checked the fast idle setting. So I will do that tomorrow with my factory manual. I did replace my choke plates when I went through the carbs because I was missing three of the little plates. So sounds like good chance I got the setting out of wack on the fast idle.

My wife has the same bike. It starts hard and it has to idle about 10 minutes before it's warm enough to move with the choke off. I've heard the carbs on these bikes don't perform well when the engine is cold.

Well carbs can be very touchy sometimes if not set properly. Before I did my re-jet kit and changed the choke plates it always fired right up and was good to go. So sounds like I am dealing with a fast idle adjustment issue from changing the choke plates and basically having to reset their locations to what I though was original. But going to reference my service manual. I will keep you guys posted after I check the factory manual and do the fast idle screw mod as listed in the link above

The choke plates, like the throttles, should be set so they are all in sync. In addition to that, their location as whole can be adjusted relative to the fast-idle mechanism. This will alter the ratio of fast-idle throttle movement to actual choke plate movement, so there is some tuning you can do to the choke system besides just the fast-idle setting.

These carbs seem to work just fine for cold starts and cold running as long as they are jetted correctly and have the choke systems working properly. Once the carbs are setup properly, you can ride it pretty quickly after a cold start. It will still need some choke as it warms up, but it should be ride-able almost right away.