i can't remember how long I went on plugs with my Gen1. 24,000 miles? I think it was 47! The threads on here if anyone wants to check. I didn't notice a difference after changing plugs but I sure felt a lot better about it. Change them as recommended by the scheduled maintenance table. Mine were in rough shape and who knows if there's molten metal flying off and doing who knows what to the engine?

To Hub, VicThing and Rook:
Sorry, I've just noticed your replies and thanks for that, I didn't notice any notification (I assume you all were adressing my post)
"Did you check the air cleaner?" I've got a K&N, which I service around every 12k miles.

"compression test", didn´t do it while I was at adjusting the valve clearances, because I was in a hurry to get the bike ready for a trip, but I'm planning to do it very soon. Because being in a hurry I misrouted the camshaft position sensor electrical lead and I hardly could connect the plugs. I have to pull off the throttle bodies again to fix it, as the lead routing goes through them. Anyway, the engine seems to have the same power as in the day I bought it and doesn't burn any oil (don't notice any level drop between oil changes - every 12k km / 7,5k miles)

About valve clearances, after 110k km / 68k miles last check:
"Valve clearance": I aimed at IN: 0,17mm / 0,0067" / EX: 0,25mm/0,010", and got close to that, except for 3 valves with a max difference of 0,001" (+0,001" on 1 intake and -0,001" on 2 exhaust valves), with all the errors that are involved.

After torquing the camshaft bridges to spec, most of the clearances got a bit tighter than before (the ones which kept the previous shims), although in most cases the same feeler blade also fit, but noticeably tighter. The front bolt of the camchain bridge was loose (!), and the right front bolt of bridge #2 (very hard to fit a torque wrench there because there's no room) was also noticeably with less torque than it should

"making HP", is not an issue for me, I think the bike has plenty of power and we have a growing number of radars / speed traps here...

"Plug threads on the used spark plugs have oil running up the threads?" No

" Plus at the nose of the porcelain show a dark tan?" I'm not sure what you mean by "nose", but at the base of the porcelain insulator, where it meets the nut where you torque the plug, they all showed a red/brownish ring except for the plug on cylinder #2

"Mine were in rough shape and who knows if there's molten metal flying off and doing who knows what to the engine"
That will happen for sure since the ground electrode takes it's toll, but I wonder at the rate it is "consumed" if it does really make any harm to an engine. Mine were all a bit thinner

About my fueling/ stalling/ misfiring/ poor fuel economy issue, any ideas/help would be appreciated. I've searched the forum but haven't found a similar problem, although I might have not searched the right way. I don't know if I should start a new topic about this
So, what's the problem and the relevant information?
Bike usually stalls when firing it up, whether ambient temperature is colder or warmer, it seems there's one or two cylinders misfiring. I've got to blip the throttle hard (until 8-9k RPM) for it to start running properly, as if something is clogged and I'm clearing it (I think it's the ECU processing new data about fueling). If I don't do that, the engine will run, but won't idle, and fuel economy figure on the dash will drop to around half of what's normal.
When ambient temperature is warmer, let's say above 22ºC / 72ºF, the problem usually doesn't show
When it's colder (below 14-15ºC / 57-59ºF) the issue comes up more frequently on the following situations:
- when I drop a gear or two to overtake someone, and have to give a bit more gas;
- when I go above 120-130 km/h / 70-80 mph;
- when I go uphill;
in short, when I charge the engine and have to give more fuel flow, and every time it happens fuel economy figure on the dash will drop to around half of what's normal.

- No FI warnings show up (if I remove any fuel injection related device, "FI error" instantly shows on the dash: I've tried with the atmospheric pressure sensor, the air intake pressure sensor, the air intake temperature sensor and with the water temperature sensor, and the respective error code is correctly read);
- spark plugs are new; after being changed, there was no noticeable difference;
- all 4 stick coil readings (high and low circuits) are within spec;
- all 4 injectors were cleaned with 2 cycles of 10' ultra-sonic cleaning and a few carb cleaner squirts. After cleansing, spray pattern seemed ok, but I didn't measure the relative fuel flow neither their electrical resistance but all seemed to be working fine;

I thought it was a fuel injector problem, but after cleaning them the problem remained.

I did recently a trip on hot weather, with the bike loaded (panniers and top case) and my wife on the back, and the issue only came up once or twice, at start up.

Sorry for the long post, I tried to give the most information possible, and thanks in advance
Antonio

* Last updated by: zzriderpt on 7/30/2024 @ 1:44 PM *

In the past, there were problems just like you are describing caused by clogged fuel filters. This was definitely the case for Gen1s, I don't know if the Gen2 was effected in the same way. The problem is that the filter inside the fuel pump causes clogs when it starts deteriorating. There was no way to remove the fuel filter inside the pump, you had to replace the whole fuel pump. There is also a secondary filter that can be changed. Some owners solved the problem just by changing the secondary filter. I hope Kawasaki changed the design of the Gen2 fuel filter to make it more serviceable.

I remember seeing a photo posted by Romans that shows a fuel pump cut in half. You can see the deterioration in the filter inside there but there's no way to change it.

If you think this might be the problem, I'd consider replacing the secondary fuel filter. I never had the problem with my Gen1 so I can't give much more info than that. I'm not even sure everythin I've told you is 100% accurate. Seems strange that there would be a permanent filter in the fuel pump but that's what I remember reading and I read it on here more than once or twice.

Hi Rook
For quite a while I've wished to have the opportunity to praise your invaluable work on behalf of the ZX14 community, and since now I have that opportunity, here it goes. I'm not a US citizen, but if I were, and since you're directly adressing to me, I want you to know that I'd surely recommend you to be awarded the US Congress Medal of Honor for having distinguished yourself by acts of valor in combat against ZX14 maintenance, mechanical or any other issues and being the Creator of the ZX14 Maintenance Bible, despite the "Gen1 Engine Subharness" Chapter doesn't state in red and bold "Those in a hurry beware to correctly rout the Engine Subharness across the throttle body holders and connect the camshaft sensor lead prior to installing back the trottle bodies", or something like that...;)

So, back to my problem, there were 3 more things I completely forgot to mention and your reply reminded me of one of them:
Just for the sake of systematization, I'll describe everything again, adding 2 more things to the list:
- Bike usually stalls when firing it up, whether ambient temperature is colder or warmer, it seems there's one or two cylinders misfiring. I've got to blip the throttle hard (until 8-9k RPM) for it to start running properly, as if something is clogged and I'm clearing it (I think it's the ECU processing new data about fueling). If I don't do that, the engine will run, but won't idle, and fuel economy figure on the dash will drop to around half of what's normal.
When ambient temperature is warmer, let's say above 22ºC / 72ºF, the problem usually doesn't show
When it's colder (below 14-15ºC / 57-59ºF) the issue comes up more frequently on the following situations:
- when I drop a gear or two to overtake someone, and have to give a bit more gas;
- when I go above 120-130 km/h / 70-80 mph;
- when I go uphill;
in short, when I charge the engine and have to give more fuel flow, and every time it happens fuel economy figure on the dash will drop to around half of what's normal;
- when I cut gas and drop gears for some distance, like when you're coasting to a stop at a freeway toll or taking a 270º freeway exit, arriving at freeway speeds.

- No FI warnings show up (if I remove any fuel injection related device, "FI error" instantly shows on the dash: I've tried with the atmospheric pressure sensor, the air intake pressure sensor, the air intake temperature sensor and with the water temperature sensor, and the respective error code is correctly read);
- spark plugs are new; after being changed, there was no noticeable difference;
- all 4 stick coil readings (high and low circuits) are within spec;
- all 4 injectors were cleaned with 2 cycles of 10' ultra-sonic cleaning and a few carb cleaner squirts. After cleansing, spray pattern seemed ok, but I didn't measure the relative fuel flow neither their electrical resistance but all seemed to be working fine;

- When throttle bodies were removed, all the vacuum hoses seemed to be in good condition and with a tight fit to the vacuum inlets;
- Fuel pump was removed and fuel filter (on the bottom and outside the fuel pump) was checked and cleaned with compressed air and gas, although it was not that dirty, and it seemed to me to be in good condition; I didn't check the fuel flow, though.

So, as you see, I removed the fuel pump and checked the external fuel pump filter. I didn't know there was another one inside the fuel pump. I'll try to find the information you mentioned.

This last information that the problem also occurs sometimes when coasting referes to a situation when the engine is not being fed by fuel, so the fuel pump delivering fuel or not is irrelevant, I thonk, which makes me think that it has nothing to do with the fuel pump. This situation happened to me exactly at the end of my trip I mentioned in my post, when I was exiting the freeway, arriving home, 2 weeks ago. The way I solved it was the usual: blip the throttle hard, to let the engine reach 8-9 RPM and after that, it gets back running fine. If I don't do that it seems that it's running only on 2 or 3 cylinders and the fuel consumption doubles (usually around 6-6,5L/100km or 36-39mpg US, and then goes to 12-14 L/100km or 17-20 mpg!).
I wonder if the problem lies in the ECU...weird gremlins living inside my ZZR...maybe COVID?...

Cheers
António

* Last updated by: zzriderpt on 7/31/2024 @ 7:00 PM *

Thank you for the wonderful compliment Antonio. If it's not the internal fuel filter, could it be the throttle sensor? There was a guy on here who solved his problem by adjusting the angle of the throttle sensor. His forum name is 44magnum. It might be worth while to look that thread up. You're never supposed to touch the throttle sensors but apparently 44magnum's got out of adjustment.

Try this... Start bike, but do not rev it. If it stalls let it. What you are doing is warming up the header pipes. Has to run less that say 3-5 seconds. Now feel every header pipe near the head. Some pipes are warm, some will be cold.

Let cool totally, swap a warm cylinder spark stick to a cold pipe. Start and see if the same cold pipe remains cold. This way it's not the spark stick. This eliminates spark as an issue.

As far as moving the TPS, I would not. Can you see that when you removed any connector to the telemetry is codes? So if the TPS was out of spec, it would code. Takes very little movement to be out of range at the TPS's elongated slots.

Short of knowing where the compression is, FI is pretty simple being that a poor runner is fuel pressure. Did you see the big black cartridge at the fuel pump assembly? The small replaceable filter is like a sewer screen call it. The black cartridge is the primary filter and that screens out super micro debris that could close the injector holes.

So it depends on how many miles are on the bike, how many times you filled the gas and the stations screens are not as efficient as the black canister to capture the micro debris. So it sounds more like a partially clogged black canister/cartridge for startup, have to rev the engine to build pressure, etc.

How many miles (km) on the bike? What year is it?

Hi Rook and Hub
Here goes an update: I think the case is closed and that the problem lied in the injectors being dirty.
Just to remember: I never had any FI error; removed the injectors and cleaned them (ultrasonic bath and a few carb cleaner squirts)
After that, in the middle of August I went with my wife on a 6k km / 3,7k mi trip. Hot weather, most of the time above 30ºC / 86ºF.
During that trip, the problem happened 3 times, only at start up, blipped the throttle and everything went back to normal again.
The first time was immediately after assembling everything together, and the second on the following day. I assume that there were residues left over in the injectors that messed up with the fuelling. The third time was a few days 3k km/ 2k mi after that, in the morning, after a bit chiller night. Never happened again while riding.
I'm waiting for the weather to cool down to have a definite conclusion, and then I'll hopefully give a final update.
To Rook:
I din't check/touch the TPS sensor. I'm waiting to make sure the problem is solved only with the injectors cleaning
To Hub:
- 2006 model, currently has about 191k km / 119k miles
- I had already done the header pipes temperature test, but I couldn't reach any conclusion, maybe I let the bike run too much time and all the headers were very hot, but I'm positive it's not spark plugs (they were changed before my trip) neither the stick coils
- No codes before, neither after reassembly
- I didn't know the black cartridge was the primary filter, on the fuel pump... I checked and blew the bottom filter with compressed air. I had a new one, but I didn't replace it because it seemed to me that the one on the fuel pump would do a better job than the new one because it had a much more closed mesh. On the mesh surface it didn't have much debris, almost any.
-"partially clogged black canister/cartridge for startup, have to rev the engine to build pressure": yes, it might be, let's wait for the weather to cool down and see what happens next.

I'll update in a month or so.

Cheers everybody, and thanks for your feedback

Thanks, zzriderpt. I have always used a full dose of Seafoam in my gas for storage and I'd even run a little bit during the riding season about every other fill. I've heard it's strong stuff and have been cautioned not to overdo it, it could be rough on delicate parts at high concentration. I believe I was using about one ounce per gallon for a full dose. I followed the directions on the bottle. They're a little ambiguous so read carefully if you use it. If it turns out this was an injector problem, the Seafoam might clear it out better and keep it clear.