Kawasaki ZZR600 Diagnose Poor Running

My Friends bike seamed to be running poor so I said I would have
a look into it.

[@ljgarrison6910]

The sigh you gave when you thought about the carbs. Kawasaki carbs are so fantastic to work on 🙄😂 I have an E3, she has her moments. Edit: over the last nine months I now have an intimate knowledge of the bikes various foybles and fixed a few.

[@milovanpuric318]

Hello there. I have zzr 600 from '91 , and there is issue somewhere between 3k and 7k, it's causing shaking , and kinda getting feeling that something is strangling her, not getting any constant acceleration , jerking and cracking .. then after 6-7k it opens up like crazy and go to the end without problem. I noticed that is heating up. Idle is also not perfect. So , i changed spark plugs , cables , battery , air and fuel filter , I changed thermostat and fluids. Now is kinda better but still acceleration in low rpm is not smooth. Thank you for reading this lines , and I will appreciate your thoughts ! All best. Milovan

[@karlnjackshomebrew1648]

Too little fuel to the carb can make it backfire. 2 bar difference in pressure is nothing and not making it run badly, most likely the carburetor.

[@chrispowell170]

What we're you spraying down the spark plug hole? I always got taught to use an old style squirt can with oil in it

[@fixitnige]

Hi chris I think it was WD40 it helps to see if the cylinder is sealing. cheers

[@chrispowell170]

@@fixitnige brilliant, thanks. Just checking to see if that would be okay using wd40 or similar not oil out of an old pump can. Cheers 👍

[@jvman4971]

on the main jet holder, normally the center goes thru the entire thing, on mine, it just goes about halfway until it hits the 4 big eholes on the sides, os that correct?

[@fixitnige]

Hello vman I think you mean the emulsion tubes ? from memory ( which is pretty bad) fuel flows into the tubes through the holes and up to the jet hole but they may be wrong.

[@Blackthumbditch]

Totally confused now. The damage to the air filter would suggest leaking intake valve. The wet compression test would suggest the same. Conclusion is piston rings? I would have sworn its a dodgy intake valve, what am I missing?

[@fixitnige]

Hi There I did later decide it may have been bad valve/Tappet but after taking to the owner they decided they did not want to go any further at the time as they were getting a new bike and would maybe sort this out at a later date. I put it back together and gave it back but heard nothing from them again about the bike. Cheers Nigel

[@2wheeltrafficbuster338]

Im with you i would say a leaking intake valve ! odds are at a guess valve seat .

[@mikefairfield7551]

Did it run any better after the carbs had been cleaned? Blocked pilots are usual culprits especially if there was bits of filter floating around, ive had several where 1st clean wasn't sufficient and would most owners notice low compression on 1cylinder? Most would an oily plug/running on 3obv

[@fixitnige]

Hello Mike, no bike ran the same when I rangthe owner and told them I could take it further to investigate they said not to bother so it never got done no idea what happened to the bike after that. cheers Nigel

[@davidjones-tz8bs]

Hi have a seized zzr 400 as it is a junker basically I would like to have crack at a rebuild, IE if I bugger it up no probs, how do I sort the cam timing and crankshaft for rebuild, trying to find video but non avail any help ?

[@fixitnige]

Hello David using a junker bike is a damm good way to start with machanics as you don't have to worry about buggering it up :) As with most engines No1 cylinder goes to top dead centre the cam should have a mark on the end which should lineup with the engine case or may have a link in the timing chain to show the correct placement. If you search you cshould be able to find a data sheet or manual.good luck Cheers Nigel

[@sheharyarkhan4429]

I have a kawasaki zzr400, it is not running on its full performance, it is continously stuttering on low rpm as well has on high rpms I have had changed the cdi but nothing is working, kindly help.

[@fixitnige]

Hi there thx for the message if my memory serves me I think the 400 cc was only an import to the uk and not a standard model here and have not had any deallings with that model but saying that I would start by stripping the carbs down and getting them sonic cleaned to make sure all the orts are clean, make sure the timing is correct and fit new spark lugs as they can often e a source of problems. Other than that I can't shed much light on the subject but I do hope you get it sorted . cheers Nigel

[@CesarRamirez-sp5nf]

Check your spark plug wire connection

[@4biFarm]

So was it the compression that was the reason it was running poorly? Because you said the number 3 spark plug was all carbon-y but the number two cylinder had low compression. So that makes it sound like theres two seperate issues there.

[@fixitnige]

Hi There your right there did seem to be 2 separate issues but the owner did not want to spend any money on the problem at that time as they were getting a new bike so I had to put it back together and return it without finding the problems. cheers Nigel

[@4biFarm]

Hey thanks for the reply! I ask because I just bought a ZZR600 that doesn't run and doesn't fire at all, so I am trying to learn about it to get it going. I know its getting fuel, because when I pulled a plug it was wet. I know theres electricity going through the plug wires because when I put a screwdriver near the end of them they zapped it. so when I get home my next order of business is to compression test and replace the spark plugs. Im not sure what else would cause it to not fire at all. I think even low compression engines usually still fire, they just don't run quite as well. I have heard it fire before but not for a while so I just don't know, my best guess is its either got foul plugs or its waaaaaay too rich and downing itself. Any Ideas?

[@fixitnige]

Hi Yoboy It does sound like it's over fueling and not getting a good spark, good idea to check the compression that may help diagnose the problem for you good luck. Cheers Nigel

[@meganshiplett8272]

Can you tell me the color of the wire that should be on my coil pack the tops of left and right ? Green or red

[@fixitnige]

Hello megan from memory the top wires are red on both sides but it has been a long time since I did this bike and there have been so many since. Good luck with your project. Nigel

[@meganshiplett8272]

G0SQI you rule and saved the day will be riding on birthday tomorrow

[@meganshiplett8272]

G0SQI just checked my setup left side coils 1-4 is black on top and on the right side 2-3 green on top red on bottom and the packs

[@donorava2178]

@@meganshiplett8272 According to the schematic on service manual red wire goes to cylinder 2 and 4 leads.

[@ljgarrison6910]

I've just bought one of these that the owner says he only get's 80mi to a tank!? This does not seem right, he has been putting in regular fuel and not high oct, could this cause it? I'm thinking needle seats or a stuck choke. I pick up the bike on the weekend - it's a 1995 ZZR600 with tbe ramair, i'm hoping I haven't just bought a pup! Hope all is well ur end, im in UK btw

[@fixitnige]

Hello LJ good to hear from you as far as your bike goes to be honest it sounds to me either the previous owner rode it to the max all the time or it has been dyno jetted or it just needs a good service. Good luck with the bike cheers Nigel

[@ljgarrison6910]

@@fixitnige Hi Nige! I never got a notification, but just came back to this and left a comment. Turns out it had been jetted, but the fuel lines were rotten, petcock was leaking and after doing that; and servicing her she ended up spanking my mates Bandit 1250 and despite my fat arse being on her, also nailed an SV1000. Very chuffed! Next i'll be taking her to a dyno. I appreciate you getting back to me and i'm so sorry I only just replied. Do I blame covid?

[@fixitnige]

@@ljgarrison6910 hi there so glad you got the bike sorted glad one of my theories was right :) hope you enjoy the bike cheers Nigel

[@schuurshot3776]

Valves or timing

[@fixitnige]

Hi Jason I think it was a leaky valve but never got the chance to find out as the owner didn't want to go any further at that time cheers.

[@greg20152015]

supposed to have WOT during compression check

[@fixitnige]

Hello Greg, if you watched the video you will have seen there were no carbs on the bike during the compression test so it could not have been more open :)

[@greg20152015]

Oops you're right. My bad!