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Do these look normal?

#1

L

Lowfatpuddin

Just did the “tune up kit” to my 2020 super z with the Kawasaki FX1000V with 50 hours. Changed my spark plugs and the original ones look like they’re running rich in my opinion. Pic included. Is this normal for these?

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#2

I

ILENGINE

Looks like running rich but could also be a too cold of a plug.


#3

R

Rivets

Because the porcelain is black but the tip is grey, I’d be checking to see as IL said too cold of a plug.


#4

Hammermechanicman

Hammermechanicman

Do you run the throttle wide open all the time? Are you running RC12YC or equvalent plug? If so i would try RC14YC plugs ans see how they look.


#5

B

Born2Mow

You can't simply take a plug out, look at it, and be able to tell anything definite. You'd need to run the engine for several minutes in its normal RPM range with new fuel and then suddenly kill it. The plugs look sooty, but that could be from idling for 15 seconds before they were pulled, or maybe the engine was stopped with the choke. Who knows ?

Plug reading is a results-based test. In order to "read" them correctly you first have to know what the engine was doing in the seconds just before. That's why some people call this a "plug chop". It's actually a "snap shot" of that specific RPM range.

You are showing us 2 plugs without the history. Therefore those plugs tell us absolutely nothing.


#6

R

Rivets

Maybe you can’t make a definitive answer when trying to diagnose a problem when looking at a spark plug, but an experienced mechanic can use it as part of their troubleshooting procedure. To you those plugs may mean nothing, but to me they give me answers to the question of where I should start with my troubleshooting of the problem. In this case experience may mean more than theory, to answ the question.


#7

B

Born2Mow

And if an answer isn't "definitive" then I hold it's not really an answer.

The OP wants an definitive answer. All I'm saying is he hasn't given us enough information to reach any such answer. More information is needed.


#8

Hammermechanicman

Hammermechanicman

Most folks misdiagnose engine issues looking at spark plugs. Spark plugs need to operate in the self cleaning temperature range which is about 950F to 1450F. Below that spark plugs will carbon foul. Every time the engine is started and until the plug reaches the self cleaning temperature it will accumulate carbon deposits. Idleing, light load and operating at less than full throttle can cause engine not to reach that temperature. Many folks look at plugs and assume the engine is running rich when in fact the engine mixture is fine and the engine is just not operating hot enough. Cars have well regulated cooling systems air cooled OPE engines don't and most are designed to not overheat running at full load in the middle of summer. Operating at a light load in cool weather may not get the plugs up to the proper temperature and they will carbon foul. "Reading" plugs takes some pracrice. It takes many hours of run time to get a good plug to read. Deposits don't change in seconds.


#9

Convert

Convert

You need to do a plug check,

The way its done with motorcycle engines is this

Run the engine under load with the engine you have that is this ;

Wide open cutting the grass etc. and with out bringing the engine to idle (keep wide open ) turn the ignition off then check the color of the plugs.

Then make your decisions based on the color of the plugs.

There are plenty of plug charts on line to help you out

Convert

Tom B


#10

VRR.DYNDNS>BIZ

VRR.DYNDNS>BIZ

Born2Mow said:
You can't simply take a plug out, look at it, and be able to tell anything definite. You'd need to run the engine for several minutes in its normal RPM range with new fuel and then suddenly kill it. The plugs look sooty, but that could be from idling for 15 seconds before they were pulled, or maybe the engine was stopped with the choke. Who knows ?

Plug reading is a results-based test. In order to "read" them correctly you first have to know what the engine was doing in the seconds just before. That's why some people call this a "plug chop". It's actually a "snap shot" of that specific RPM range.

You are showing us 2 plugs without the history. Therefore those plugs tell us absolutely nothing.
Click to expand...
I agree but also agree with prior comment that RC14yc is better. We see that as almost a normal change on so many units, it becomes habit. These are not a full heat range hotter, only a half or 3/4 step up.


#11

G

Grdate

Have you experienced a rich condition on cold starts or even hot starts, like black smoke? I have a 2021 gravely Mach with the fx921 and 10 hours that has the same plug readings. I am also getting black smoke on startups. I have installed new plugs and performed WOT cuts with no time idling, and get the same plug readings. Just wondering if you had any updates on a fix?


#12

VRR.DYNDNS>BIZ

VRR.DYNDNS>BIZ

wHAT DO YOU MEAN "pLUG rEADINGS"


#13

G

Grdate

VRR.DYNDNS>BIZ said:
wHAT DO YOU MEAN "pLUG rEADINGS"
Click to expand...
The overall condition of the plug that I can visually see.


#14

Glades Cat

Glades Cat

Have you checked/ replaced the air filter. Of course, a plugged up filter will choke an engine.
Yea, they look sooty.


#15

G

Grdate

Glades Cat said:
Have you checked/ replaced the air filter. Of course, a plugged up filter will choke an engine.
Yea, they look sooty.
Click to expand...
Yeah, the mower is brand new. No obstructions in the intake to speak of. I think I have narrowed it down to the tank vents not relieving pressure from the tanks. I can remove the fuel caps on each tank and the pressure exhaust outta the tanks. The tank vent valves have a duck bill check valve that is restricting the pressure to relieve to the intake elbow. I believe the tanks are pressurizing during storage and during operation causing the fuel to force past the float needle. There was a puddle of fuel in the intake when I pulled the carb off.


#16

VRR.DYNDNS>BIZ

VRR.DYNDNS>BIZ

Grdate said:
Yeah, the mower is brand new. No obstructions in the intake to speak of. I think I have narrowed it down to the tank vents not relieving pressure from the tanks. I can remove the fuel caps on each tank and the pressure exhaust outta the tanks. The tank vent valves have a duck bill check valve that is restricting the pressure to relieve to the intake elbow. I believe the tanks are pressurizing during storage and during operation causing the fuel to force past the float needle. There was a puddle of fuel in the intake when I pulled the carb off.
Click to expand...
The system is for evaporative emissions. There are many designs. The typical new generators have a vent line to the air box connected to the valve on the top of the tank. Many people fill the tank to the top, not paying attention to the do not fill above point. If they do fill that above this point, then while running, this line can suck gas thru the system, usually hitting the charcoal cannister first, saturating it with gas , the non to the intake. For this system to draw gass fumes to the cannister to avoid the all damaging fumes to our air, a vacuum as well as static vent thru the cannister is designed to hold those fumes and when running, it tends on a proper system to dry the charcoal of anything collected. These systems are not perfect. As an example, a near full tank of gas, then being moved around can slosh gas into the system, and gravity then carries it to the cannister where it lays waiting for the next run, causing a very rich system. ON a mower, while being used this can be worse in that a full tank on a bumpy sloped travel is going to suck fuel in and feed fuel in excess.


#17

Hammermechanicman

Hammermechanicman

You need to run the engine harder or run the next hotter step plugs.


#18

G

Grdate

VRR.DYNDNS>BIZ said:
The system is for evaporative emissions. There are many designs. The typical new generators have a vent line to the air box connected to the valve on the top of the tank. Many people fill the tank to the top, not paying attention to the do not fill above point. If they do fill that above this point, then while running, this line can suck gas thru the system, usually hitting the charcoal cannister first, saturating it with gas , the non to the intake. For this system to draw gass fumes to the cannister to avoid the all damaging fumes to our air, a vacuum as well as static vent thru the cannister is designed to hold those fumes and when running, it tends on a proper system to dry the charcoal of anything collected. These systems are not perfect. As an example, a near full tank of gas, then being moved around can slosh gas into the system, and gravity then carries it to the cannister where it lays waiting for the next run, causing a very rich system. ON a mower, while being used this can be worse in that a full tank on a bumpy sloped travel is going to suck fuel in and feed fuel in excess.
Click to expand...
Thank you, I am in the process of trying to find an older style vented cap with the same threads and deleting the evaporative vent line and plugging the vent valve.


#19

G

Grdate

Hammermechanicman said:
You need to run the engine harder or run the next hotter step plugs.
Click to expand...
It’s hard to actually run a mower harder than normal when they are governed to 3600. I believe mowing thicker grass would actually demand more fuel based on the increased load. I have tried the ngk BPR4ES which is one step hotter than the stock BPR5ES.


#20

Hammermechanicman

Hammermechanicman

These engines have no temperarure regulation. They are designed to operate at full load at a fairly high ambient temperature. Spark plugs need to operate at about 1000 degrees to be in the self cleaning range. Engines not run at a high enough load to get the engine temp high enough will carbon foul plugs regardless of the mixture. Moat engines today are jetted on the lean side. How does the engine run? Black smoke? Missing? Stumbling on accelerating?


#21

G

Grdate

The mower runs great, just a puff of black smoke on cold and hot starts. I have started raising throttle position to 75% during cold starts to allow a quicker volume of air to enter once the choke is set to 0% after the engine hits


#22

G

Grdate

I have ordered leaner jets, #131 and #137, and will see if the problem still exist. I would love to adjust the idle mixture screw, but you know they would limit access with a plug.


#23

G

Grdate

Lowfatpuddin said:
Just did the “tune up kit” to my 2020 super z with the Kawasaki FX1000V with 50 hours. Changed my spark plugs and the original ones look like they’re running rich in my opinion. Pic included. Is this normal for these?
Click to expand...
Problem solved on a FX921. Apparently 93 ethanol free fuel is too slow and cool of a burn for this engine. Switched to 87, just as the Kawasaki manual states, and no more fouled plugs.


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