KZ1100 missfires and dies at idle when warm

Quickv4 · 12-05-2012, 11:21 AM

I just got a 1982 kz1100a as a project. Got it running. Thoroughly cleaned and set the carbs, made sure the airbox boots seated properly and had no vaccume leaks.

The bike runs good when cold, pulls hard, idles well. However, as it warms up, it will refuse to idle and will hiccup when accelrating hard.
When I pull the plugs from when it stalls at idle, all are black, not wet, but dry black, indicating a rich condition or maybe ignition problems?

Im thinking it may be either the coils or ignition pickups..?

Here is a video from a somewhat cold start to warm up...

http://m.youtube.com/watch?v=bCs6_G8VlUM

Dave in Wi · 12-05-2012, 04:18 PM

Kind of sounds ignition related to me if it runs worse as it warms up.

Tosh Togo · 12-05-2012, 05:28 PM

Quote:

Originally Posted by Dave in Wi

Kind of sounds like it's too rich to me if it runs worse as it warms up.

Fixt.

manxkipper · 12-06-2012, 02:53 AM

Sounds similar to the issue I had many years ago with my Z1300. One of the ignition pickup coils (it had 3) was faulty and only at idle when hot. I assumed the coil was breaking down with heat. Replaced it with one from a Z1000J. No problem thereafter.

Dave in Wi · 12-07-2012, 05:21 AM

Quote:

Originally Posted by Tosh Togo

Fixt.

Entirely possible. What's that old saying, most electrical problems are carb related?

Quickv4 · 12-07-2012, 06:03 AM

If it is fuel related, why are all four plus indicating rich?

When I rebuilt the carbs, I did not replace the orings for the pilot jet plugs. Ive read that these plugs force the piolt jet to siphon fuel through the main jet instead of the float bowl. Maybe they are leaky, and the idle jets are sucking in too much fuel??

anotherguy · 12-07-2012, 07:33 AM

Do you have access to a four gas analyzer?

channelcat · 12-08-2012, 08:41 PM

if you did not replace the pilot jet o-rings, you did not rebuild the carbs. basic. thanks for the reminder.
http://www.youtube.com/watch?v=CKVMl2Ft_gU

metalmechanic · 12-09-2012, 07:14 PM

Sounds like Ur condenser or capacitor for your ignition is shot. Easy fix. I could be wrong tho.... :)

12-05-2012, 11:21 AM	#1
Quickv4 ^OP Pro Turd Polisher Joined: Jul 2009 Location: Foote of duh Lake, Wiscowsin Oddometer: 523	KZ1100 missfires and dies at idle when warm I just got a 1982 kz1100a as a project. Got it running. Thoroughly cleaned and set the carbs, made sure the airbox boots seated properly and had no vaccume leaks. The bike runs good when cold, pulls hard, idles well. However, as it warms up, it will refuse to idle and will hiccup when accelrating hard. When I pull the plugs from when it stalls at idle, all are black, not wet, but dry black, indicating a rich condition or maybe ignition problems? Im thinking it may be either the coils or ignition pickups..? Here is a video from a somewhat cold start to warm up... http://m.youtube.com/watch?v=bCs6_G8VlUM __________________ Jerry ____________________________ Great forum and Resource for 1st and 2nd gen Honda V4s SabMagIntercept www.v4hondabbs.com

12-05-2012, 04:18 PM	#2
Dave in Wi Beastly Adventurer Joined: Feb 2007 Location: 40 Square Miles Surrounded By Reality (Madison Wi) Oddometer: 1,462	Kind of sounds ignition related to me if it runs worse as it warms up. __________________ Dave in WI 2002 ZRX1200R 1975 XL100 1988 DT50 "Daddy, it's five o'clock sometime!"

12-06-2012, 02:53 AM	#4
manxkipper Fishpistel Joined: Jan 2006 Location: Cape Town Oddometer: 230	Sounds similar to the issue I had many years ago with my Z1300. One of the ignition pickup coils (it had 3) was faulty and only at idle when hot. I assumed the coil was breaking down with heat. Replaced it with one from a Z1000J. No problem thereafter. __________________ Aprilia Tuono Norton 650 Mercury Moto Guzzi LM2 1936 BSA Y-13 Project

12-07-2012, 06:03 AM	#6
Quickv4 ^OP Pro Turd Polisher Joined: Jul 2009 Location: Foote of duh Lake, Wiscowsin Oddometer: 523	If it is fuel related, why are all four plus indicating rich? When I rebuilt the carbs, I did not replace the orings for the pilot jet plugs. Ive read that these plugs force the piolt jet to siphon fuel through the main jet instead of the float bowl. Maybe they are leaky, and the idle jets are sucking in too much fuel?? __________________ Jerry ____________________________ Great forum and Resource for 1st and 2nd gen Honda V4s SabMagIntercept www.v4hondabbs.com

12-07-2012, 07:33 AM	#7
anotherguy Beastly Adventurer Joined: Jun 2009 Location: in the foothills now.... Oddometer: 4,315	Do you have access to a four gas analyzer? __________________ When injustice becomes law,resistance becomes duty. Thomas Jefferson

12-08-2012, 08:41 PM	#8
channelcat Gnarly Adventurer Joined: Sep 2006 Oddometer: 171	if you did not replace the pilot jet o-rings, you did not rebuild the carbs. basic. thanks for the reminder. http://www.youtube.com/watch?v=CKVMl2Ft_gU

12-09-2012, 07:14 PM	#9
metalmechanic Mechanical rider Joined: Dec 2012 Oddometer: 1	Sounds like Ur condenser or capacitor for your ignition is shot. Easy fix. I could be wrong tho.... :)

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