Intermittent dropping cylinders on k2 - ZX Forums
 
LinkBack Thread Tools
post #1 of 15 (permalink) Old 08-29-2019, 08:22 PM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
Intermittent dropping cylinders on k2

Recently my k has started to not fire on a couple cylinders at low rpm”s when it gets warm? Starts up fine and idles good for a few minutes and just dies. Hard restarting doesn’t want to run smooth below about 4000 rpm. Any help greatly appreciated. Thank you in advance.
Attached Thumbnails
Click image for larger version

Name:	5AD6240F-0D3B-42A6-A5F2-B9BF13A6764E_1567135306049.jpeg
Views:	23
Size:	1.21 MB
ID:	10708  
Johnnyo556 is offline  
Sponsored Links
Advertisement
 
post #2 of 15 (permalink) Old 08-31-2019, 05:15 AM
Senior Member
 
motocon's Avatar
 
Joined: Oct 2008
From: Ontario
I Ride: 99ZX7R (street) 98 ZX7R (track). 89 ZX10

Posts: 758
I would start with the easy stuff.
Note and confirm which 2 cylinders are not firing when warm.
Those bikes have 2 coils that each fit 2 cylinders. I believe 1-4 and 2-3.
Then swap the coils and see if the same 2 cylinders drop off.
A simple plug wire can cause grief too.
Text the pick up coil.
The running smooth issue and hard starting sound to be fuel related.(if the ignition stuff all passes)
Could be needle valves are not sealing, pilot jets etc.
Take your time and write everything down as you go through the bike.

If you have not made any recent changes to the bike it is likely something simple.

Don’t lose faith.....
motocon is offline  
post #3 of 15 (permalink) Old 08-31-2019, 10:41 PM
Senior Member
 
mte78's Avatar
 
Joined: Feb 2018
From: San Diego

Posts: 442
That Hindle exhaust looks great. Good luck with finding the gremlins.
mte78 is online now  
 
post #4 of 15 (permalink) Old 09-01-2019, 06:00 AM
Senior Member
 
ninjanut's Avatar
 
Joined: Dec 2011
From: hamilton,ON,Canada
I Ride: 1996 ZX7R, 1996 ZX7RR (track)

Posts: 2,053
Also try simply trimming the wires and reinstalling the caps on the wires.
ninjanut is offline  
post #5 of 15 (permalink) Old 09-01-2019, 11:56 AM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
Thanks guys!
If it is a coil what other model and years are compatible with the 91-92 k’s ?
Johnnyo556 is offline  
post #6 of 15 (permalink) Old 09-01-2019, 12:59 PM
57x
7777
 
57x's Avatar
 
Joined: Apr 2010
From: Aromas, CA
I Ride: 2018 H2 SX SE, 2005 Z750S, ZX7R Superbikes

Posts: 6,501
Quote:
Originally Posted by Johnnyo556 View Post
Thanks guys!
If it is a coil what other model and years are compatible with the 91-92 k’s ?
91-03 ZX7/ZX7R

The parts list shows a difference by year, but I have swapped them across years several times.

Start with wires first. It is often the issue. Most coil failures I have seen on these are heat related. Great when cold and failure when hot, back working again when cold. Pull all the coil nuts, push the cap back with the washer and trim them at the line on them, around a quarter inch and reattach them. If this does not fix this then move to coils.
57x is online now  
post #7 of 15 (permalink) Old 09-01-2019, 05:50 PM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
Ok thanks I will try that this week. I also did just put in a new battery but not a Yuasa... could that also be part of the problem ?
Johnnyo556 is offline  
post #8 of 15 (permalink) Old 09-04-2019, 05:53 AM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
How do I test the pick up coil?
Johnnyo556 is offline  
post #9 of 15 (permalink) Old 09-04-2019, 07:36 AM
Senior Member
 
Joined: Oct 2014
From: Calgary

Posts: 266
Battery brand should not matter. Swap the coils and see if issue comes up again. Easiest way.
evan_calgary is offline  
post #10 of 15 (permalink) Old 09-06-2019, 01:22 PM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
Coils test good so I’m digging deeper!
Attached Thumbnails
Click image for larger version

Name:	E666E9CD-1F23-40F3-A7E1-050CA2959F6D_1567801364096.jpeg
Views:	6
Size:	1.23 MB
ID:	10740  
Johnnyo556 is offline  
post #11 of 15 (permalink) Old 09-06-2019, 03:55 PM
Senior Member
 
motocon's Avatar
 
Joined: Oct 2008
From: Ontario
I Ride: 99ZX7R (street) 98 ZX7R (track). 89 ZX10

Posts: 758
Sid u meter them or actually swap them and ride?
Sometimes coils test fine but when they get hot things start to fail.
Did you take Ninjamut’s advice and cut 1/4 inch off each plug wire and reattach? I did both my bikes years ago and it solved a similar issue.
motocon is offline  
post #12 of 15 (permalink) Old 09-06-2019, 04:57 PM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
I just tested all the components with a meter and everything was in spec so I figured while I had it apart I’d clean the carbs again.
Johnnyo556 is offline  
post #13 of 15 (permalink) Old 09-06-2019, 05:20 PM
Senior Member
 
motocon's Avatar
 
Joined: Oct 2008
From: Ontario
I Ride: 99ZX7R (street) 98 ZX7R (track). 89 ZX10

Posts: 758
If you’re into carbs I would replace all the needle valves.
Careful not to bounce back and forth when fault finding and keep track of what you are doing and the results of each step.
You’ll get this👍
motocon is offline  
post #14 of 15 (permalink) Old 09-06-2019, 08:44 PM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
Yes already ordered new needle valves today.
Just take a look at these pics... the number 1 cylinder intake valve chamber only on the left has a little browning going on (1st pic) and all the rest are spotless(2nd pic) mean anything?
Attached Thumbnails
Click image for larger version

Name:	59EA12EF-6C06-4ED1-8674-E52967DA5095_1567827668749.jpeg
Views:	12
Size:	132.3 KB
ID:	10744   Click image for larger version

Name:	C6FD3C4C-6D70-459E-973E-B8B33C9A537D_1567827741236.jpeg
Views:	12
Size:	236.4 KB
ID:	10748  
Johnnyo556 is offline  
post #15 of 15 (permalink) Old 09-12-2019, 09:04 AM Thread Starter
Newbie
 
Johnnyo556's Avatar
 
Joined: Aug 2019

Posts: 10
#2 carb had some crap clogging the slow pilot jet. Idles good now but haven’t taken it out to see if that cleared it all up.
Johnnyo556 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the ZX Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome