Kawasaki Ninja ZX-6R Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1 (Edited)
Hello guys,
Back in Feb 19 I've got my '13 zx636, fully serviced, running smoothly. In the summer of the same year i got the ECU flashed on a dyno run.
Fast forward to Dec' 19, I went to a trip to Brasil ( I am from Israel) for a month and a half, so i had to let my bike stand still for that duration. I left it after an oil and an oil filter change (Putoline Nano tech 4+), with a full gas tank, and the battery unplugged.
After i got back, I had a hard time starting it back up again. It took many attempts, but finally got the engine running and warm up.
Some issues have risen:
1. On a cold start, the revs go up, and fall down immediately to 1k-800 rpms. It takes like 4-8 seconds for it to go to 2K rpms to warm up properly. If It's early in the morning, and cold enough, when the revs fall to 800 rpm, the bike will shut off completely, and only warm up from a second start attempt. If I try to move the throttle even a tiny bit while at 1k-800 rpm, the bike shuts off. Only when back to 2k he allows to use the throttle.
2. My fuel consumption went up by about x1.3, with the same riding style. From 16 km per liter to 12 km/l.
3.The sound of the bike changed. sounds almost like a three cylinder engine. The firing sequence seems not to be aligned properly.

I went to my mechanic. After about 4 hours of work he said the cylinders 3-4 had a way lower vacuum readings. cylinder 1 was around 160, cylinders 2-3 around 140, and cylinder 4 around 120. He tried to align them and did a pretty good job, but still not perfect. The O rings went dry and created problems with the vacuum and he got them swapped. The bike sounds way better and healthier now, but issues 1 and 2 still present.
My next step is going to be to try to cold start the bike on a dyno, while he rested for a whole night outside and got as cold as possible. Maybe we will see some useful info.

I am need of any kind of help and ideas guys! I think that the issues might not be related to one another but i cant be sure. Too many variables have changed. When i left for Brasil it was still warm in Israel, and when i got back, it got very cold.
I am not sure what to think of it.
Might it be that the bad vacuum readings are just a symptom of a bigger issue?
I need any kind of help i can get. And ideas.

I have a cat delete and a Yosh RS4 exhaust. The bike does 110 HP on a dyno.
 

·
Registered
Joined
·
152 Posts
I would change gas and spark plugs. The cold start almost sounds like mine. Sometimes it takes me a couple of times before it will settle into a decent idle.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #3
I would change gas and spark plugs. The cold start almost sounds like mine. Sometimes it takes me a couple of times before it will settle into a decent idle.
I have ridden 3-4 gas tanks already. The mechanic said the spark plugs are fine.
 

·
Registered
Joined
·
12,563 Posts
Clogged fuel filter
Fuel pump going bad
Bad fuel injector
Bad O2 sensor

Its gotta be one of those.
 

·
Registered
Joined
·
94 Posts
My 15 is somewhat similar- during cold starts it don't die, but it stays at 800rpm for about 5 seconds before enrichment starts and climbs to 2,000. Not 100% sure but I think most of the 13-18 zx6r's have this delay. Yours is a 13 correct? First so many ecu's manufactured have turned out defective (no official recall, but check part# on lot manufacturing tag) - similar to some of the same problems your describing and can happen at random even after running fine for months. I believe there's a 13 zx6r issues thread here that lists the good and defective part #. Oh and also- what's your warm idle set at? Too low idle can cause a similar problem.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #6
Clogged fuel filter
Fuel pump going bad
Bad fuel injector
Bad O2 sensor

Its gotta be one of those.
I got my O2 sensor removed when got my cat deleted. I din't have any issues with it before.
How can the fuel pump be checked? Is it pressure check?
 

·
Registered
Joined
·
17 Posts
Discussion Starter #7
My 15 is somewhat similar- during cold starts it don't die, but it stays at 800rpm for about 5 seconds before enrichment starts and climbs to 2,000. Not 100% sure but I think most of the 13-18 zx6r's have this delay. Yours is a 13 correct? First so many ecu's manufactured have turned out defective (no official recall, but check part# on lot manufacturing tag) - similar to some of the same problems your describing and can happen at random even after running fine for months. I believe there's a 13 zx6r issues thread here that lists the good and defective part #. Oh and also- what's your warm idle set at? Too low idle can cause a similar problem.
Warm idle is somewhere between 1.2-1.3. Enriching the idle rpm doesn't help with cold starts.
How does the fact that my fuel economy got way worse fit into all of this?
 

·
Registered
Joined
·
12,563 Posts
I got my O2 sensor removed when got my cat deleted. I din't have any issues with it before.
How can the fuel pump be checked? Is it pressure check?
I meant the intake air pressure sensor. Its hooked up to the throttle bodies and measures vacuum.
——————————————-

Fuel pump has a mesh strainer/filter attached to it. Sometimes it can get dirty enough where it blocks fuel suction.

Fuel pump is usually checked with a special pressure gauge. But I usually disconnect a fuel line and point it away somewhere. If it shoots out fuel more than 5 feet away then its probably good. Or cover the end of the hose with ur finger and see if its building up pressure.
—————————————————————

Batcycle is correct. The ‘13 models had issues with cold starts when they first came out. I think the solution was an ECU reflash by Kawasaki but Im not 100% sure. There is a thread somewhere on this forum with a lot of info about it.
 

·
Registered
Joined
·
12,563 Posts
Warm idle is somewhere between 1.2-1.3. Enriching the idle rpm doesn't help with cold starts.
How does the fact that my fuel economy got way worse fit into all of this?
The fact that your fuel economy got way worse is what leads me to believe its not the infamous 2013 cold start issue. Also, bump tour warm idle to 1600. 1200 is too low.


Btw, how does the power feel when u ride it?
 

·
Registered
Joined
·
17 Posts
Discussion Starter #10
I meant the intake air pressure sensor. Its hooked up to the throttle bodies and measures vacuum.
I think that this had been done, I've written about it. The vacuum measure numbers were off in cylinder 1 and 4. Cylinder one had a reading of 160 and cylinder 4 had a reading of 120. The mechanic said that cylinder 4 was getting some air in. I figure that's why the bike sounded off and not like a 4-cylinder engine. Got it kinda aligned and swapped the dry O-rings, so the vacuum seal can be created correctly. The bike sounds good now. I figure the vacuum is good now.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #11
I meant the intake air pressure sensor. Its hooked up to the throttle bodies and measures vacuum.
––––––––––––––-

Fuel pump has a mesh strainer/filter attached to it. Sometimes it can get dirty enough where it blocks fuel suction.

Fuel pump is usually checked with a special pressure gauge. But I usually disconnect a fuel line and point it away somewhere. If it shoots out fuel more than 5 feet away then its probably good. Or cover the end of the hose with ur finger and see if its building up pressure.
–––––––––––––––––––––

Batcycle is correct. The ‘13 models had issues with cold starts when they first came out. I think the solution was an ECU reflash by Kawasaki but Im not 100% sure. There is a thread somewhere on this forum with a lot of info about it.
The fact that your fuel economy got way worse is what leads me to believe its not the infamous 2013 cold start issue. Also, bump tour warm idle to 1600. 1200 is too low.


Btw, how does the power feel when u ride it?
1600? The manual says 1400...
After the O-ring swap, the power feels way better. It's hard to compare when you ride it all the time.
I guess I will have the fuel pump checked next. Could the pump be the culprit of bad fuel economy?
 

·
Registered
Joined
·
3,755 Posts
I think that this had been done, I've written about it. The vacuum measure numbers were off in cylinder 1 and 4. Cylinder one had a reading of 160 and cylinder 4 had a reading of 120. The mechanic said that cylinder 4 was getting some air in. I figure that's why the bike sounded off and not like a 4-cylinder engine. Got it kinda aligned and swapped the dry O-rings, so the vacuum seal can be created correctly. The bike sounds good now. I figure the vacuum is good now.
1600? The manual says 1400...
After the O-ring swap, the power feels way better. It's hard to compare when you ride it all the time.
I guess I will have the fuel pump checked next. Could the pump be the culprit of bad fuel economy?
I had a stick coil go bad on mine a while back. It sounded like a triple instead of an inline 4, and the fuel economy was a lot worse. Here is a video I made showing what it sounded like:

 

·
Registered
Joined
·
94 Posts
By any chance does your oil happen to smell like gas? Change in its sound could possibly be bad stick coil- did you ride it much after the reflash before you left? O2 sensor should have final "say so" fueling wise but should've been deleted in the reflash..... I'd smell oil first, check header temps (no temp gun then spray water on them), pull and inspect plugs. I'm assuming "aligning" meant fitting the throttle bodies inside the rubber boots but surely they changed the plugs and synced the throttle bodies after changing the idle sync screw o-rings? Either way- those three checks should give you some kind of lead.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #14
By any chance does your oil happen to smell like gas?
I have no idea, Ill figure a way to do that asap haha.
Change in its sound could possibly be bad stick coil- did you ride it much after the reflash before you left? O2 sensor should have final "say so" fueling wise but should've been deleted in the reflash.....
I ride the bike every day. I've ridden 15k km over a year. O2 sensor has been deleted and the butterfly has been turned off.
I'd smell oil first, check header temps (no temp gun then spray water on them), pull and inspect plugs.
What do you mean by checking header temp? What should or shouldn't be?
I'm assuming "aligning" meant fitting the throttle bodies inside the rubber boots but surely they changed the plugs and synced the throttle bodies after changing the idle sync screw o-rings?
Yes.

I have left my bike at the Dyno test garage today, we will give it a run and see if we can get some useful info from it. We are also looking at f/a ratio on bone cold start.
 

·
Registered
Joined
·
12,563 Posts
Header test= From a cold engine, start it and keep touching the headers to see if one of them is staying cold. U can tell which cylinder isnt working that way.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #16
Header test= From a cold engine, start it and keep touching the headers to see if one of them is staying cold. U can tell which cylinder isnt working that way.
They are all working fine.

My A/F ratio on cold start is around 14, which is good. Still, if I try to give it gas, it chokes. Only when reaching 2k RPM, it doesn’t die from adding gas.
 

·
Registered
Joined
·
94 Posts
That's somewhat lean a/f ratio for cold start- i set the target for my 15 at 12.5 (12.8 for economy map), but unless you manually dial it in (which I don't) the bazzaz don't touch fueling at idle. Can't remember for the life of me what mine runs exactly, but I'm pretty sure it's 13.3-13.5. Unless your enrichment map has been modified, you may possibly have unmonitored air entering (slightly lean idle afr, and when dyno tuned injector duty cycle is increased to compensate thus causing excessive fuel consumption). The boots and clamps under the throttle body assembly are usually the culprit- torn boot or bent clamp not sealing tightly around the boot outer diameter.
 

·
Registered
Joined
·
94 Posts
One thing i'll mention- I've noticed many of the 13+ models seem to have a delay running enrichment on cold starts (idles at 800 rpm for 3-5 seconds before increasing to 2,000). It's something to do with the signal the ecu receives from the coolant temp sensor...... it may read within spec, but possibly slow sending or ecu slow calculating the signal. Mine don't die, but does have have a delay before reaching 2,000.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #19 (Edited)
That's somewhat lean a/f ratio for cold start- i set the target for my 15 at 12.5 (12.8 for economy map), but unless you manually dial it in (which I don't) the bazzaz don't touch fueling at idle. Can't remember for the life of me what mine runs exactly, but I'm pretty sure it's 13.3-13.5.
AFR at hot idle is 13.8-14. AFR at cold start I don't exactly remember, but we tried to enrich the mixture to see if this helps, and it doesn't.
In any case, the dyno guy didn't touch the idle fuel ratios, and we do not have access to a fuel map which changes by air temp.
Unless your enrichment map has been modified, you may possibly have unmonitored air entering (slightly lean idle afr, and when dyno tuned injector duty cycle is increased to compensate thus causing excessive fuel consumption). The boots and clamps under the throttle body assembly are usually the culprit- torn boot or bent clamp not sealing tightly around the boot outer diameter.
We tuned the map back in August. the fuel consumption problem persists after the bike stood still for a month and a half, almost half a year later.
Yesterday we didn't change the map, the dyno still shows good AFR, we didn't monitor any problem.
Might it be the case that I do have an unmonitored air entering, so the ECU enriches my AFR, to get the 14 ratio, and that what causes extensive fuel consumption? I don't think that's logical. The ECU first sees how much air is available, and adds fuel accordingly, to get the 14 ratio. Oh wait, now it is logical! If, say, at first the air was X and fuel was Y, and we got 14, now air is 1.3X and it increases the fuel to 1.3Y. Is this possible?!
 

·
Registered
Joined
·
17 Posts
Discussion Starter #20
One thing i'll mention- I've noticed many of the 13+ models seem to have a delay running enrichment on cold starts (idles at 800 rpm for 3-5 seconds before increasing to 2,000). It's something to do with the signal the ecu receives from the coolant temp sensor...... it may read within spec, but possibly slow sending or ecu slow calculating the signal. Mine don't die, but does have have a delay before reaching 2,000.
Is it possible to change that sensor?
 
1 - 20 of 29 Posts
Top