Export thread

Nikki carburetor 2019 Kawasaki Mule SX KAF400

#1

M

MParr

This Mule has always run rich and carbon fouls plugs. It’s getting to where it will need rebuilding or replacing. Is there a replacement Walbro carburetor available for this Mule?


#2

StarTech

StarTech

Might be simpler to rebuild the carburetor and install a leaner jet.

You have a choice of 99, 102, 105, and 109 that leaner than the 112 that supposedly was factory jet.

Or order a new carburetor and leaner jet.

Might be trial and error on which one to use.


#3

M

MParr

StarTech said:
Might be simpler to rebuild the carburetor and install a leaner jet.

You have a choice of 99, 102, 105, and 109 that leaner than the 112 that supposedly was factory jet.

Or order a new carburetor and leaner jet.

Might be trial and error on which one to use.
Click to expand...
That’s what I was thinking. I’m going to try a few more things in the morning. I’m going to recheck the choke cable adjustment. I’m going to pull the cover off of the mixture screw and see if I can fine tune it. If that fails, I will put a rebuild kit in it and smaller jet. I was hoping there was a Walbro replacement.
Thanks.


#4

M

MParr

@StarTech
I think that I’ll order a #109 and #105.


#5

Scrubcadet10

Scrubcadet10

put a BPR4ES spark plug in it. I've worked on several 600 series mules that fouled plugs, went up to BPR4ES from the stockc 6ES and that usuallys fixes them.


#6

S

slomo

What is the jet size for high altitudes? I see no mention for an HA main jet.

Make sure the needle/seat holds at 7psi.

Carb float level?

How bad is the fouling? Pictures please.


#7

StarTech

StarTech

1727737429803.png
Jet for high altitude get smaller as altitude is increased. Note jet sizes are in hundredth of a millimeter. And they are usually marked.


#8

M

MParr

Scrubcadet10 said:
put a BPR4ES spark plug in it. I've worked on several 600 series mules that fouled plugs, went up to BPR4ES from the stockc 6ES and that usuallys fixes them.
Click to expand...
I already have. It hasn’t helped.
I currently have Champion RN14YC in it.
I thought of putting a BPR2ES in it.
The carbon fouling/rich condition seems to be fairly common in these Kawasaki Mule SX KAF400.


#9

M

MParr

StarTech said:
View attachment 69765
Jet for high altitude get smaller as altitude is increased. Note jet sizes are in hundredth of a millimeter. And they are usually marked.
Click to expand...
Right, the #112 is the stock jet.
However, the Kawasaki FJ400D engine lists a #110 as the stock jet.


#10

M

MParr

slomo said:
What is the jet size for high altitudes? I see no mention for an HA main jet.

Make sure the needle/seat holds at 7psi.

Carb float level?

How bad is the fouling? Pictures please.
Click to expand...
Pretty bad. It’s done it for a while now. I’m going to tweak it a little and adjust the choke cable as described in the service manual.
If that doesn’t work, I will order the jets, gaskets, and a new needle. I may order a new float too.


#11

S

slomo

StarTech said:
View attachment 69765
Jet for high altitude get smaller as altitude is increased. Note jet sizes are in hundredth of a millimeter. And they are usually marked.
Click to expand...
Agree. Some carbs offer high altitude mains for less fueling at altitude. In this case we see a variety of sizes.


#12

M

MParr

I went back over all of the adjustments to the choke, low idle, and accelerator stop. I also went to a BPR2ES spark plug. The valves have been adjusted to .005. The thing idles so smooth. It cranks really easy. I’m going to run it a while and check the spark plug for carbon fouling. I prepared to remove the carburetor and change the main jet, float, and needle. We will see how it goes.


#13

S

slomo

I know these are simple mower engines. Running a super hot plug could lead to pre ignition pings. Probably never happen in a mower engine. Not enough load I would guess. I would stick to the stock heat range and deal with the main jet sizing down from 112.

Post up a pic or video of the fouling. Would give us an idea of how much smaller to go on the main.

Make sure she is not passing excess fuel from the needle. Float level the same. Choke plate wide open. Remove air filter for testing. I've had perfectly clean "looking" filters act like the choke was on. New air filter, she ran like a top.


#14

Tiger Small Engine

Tiger Small Engine

slomo said:
I know these are simple mower engines. Running a super hot plug could lead to pre ignition pings. Probably never happen in a mower engine. Not enough load I would guess. I would stick to the stock heat range and deal with the main jet sizing down from 112.

Post up a pic or video of the fouling. Would give us an idea of how much smaller to go on the main.

Make sure she is not passing excess fuel from the needle. Float level the same. Choke plate wide open. Remove air filter for testing. I've had perfectly clean "looking" filters act like the choke was on. New air filter, she ran like a top.
Click to expand...
Carbon fouling plug can also be a weak ignition coil(s). Going two plus heat ranges hotter on spark plug may not be the answer in a mower. More something that is done in an older two stroke quad or dirt bike.


#15

M

MParr

slomo said:
I know these are simple mower engines. Running a super hot plug could lead to pre ignition pings. Probably never happen in a mower engine. Not enough load I would guess. I would stick to the stock heat range and deal with the main jet sizing down from 112.

Post up a pic or video of the fouling. Would give us an idea of how much smaller to go on the main.

Make sure she is not passing excess fuel from the needle. Float level the same. Choke plate wide open. Remove air filter for testing. I've had perfectly clean "looking" filters act like the choke was on. New air filter, she ran like a top.
Click to expand...
I threw the old plug away.
The air filter is a new OEM Kawasaki.
I plan on ordering the parts shortly.


#16

M

MParr

Tiger Small Engine said:
Carbon fouling plug can also be a weak ignition coil(s). Going two plus heat ranges hotter on spark plug may not be the answer in a mower. More something that is done in an older two stroke quad or dirt bike.
Click to expand...
This is a Kawasaki FJ400D in a Kawasaki Mule. The carbon fouling is pretty common in these things.
The FJ400D is also used in EZ-GO golf carts and John Deere Gators. The standard jet for the EZ-GO is a #110 for sea level to 3,000’ above sea level. I will definitely need a smaller jet.


#17

S

slomo

Did you get this ironed out yet? What was the fix action please?


#18

M

MParr

slomo said:
Did you get this ironed out yet? What was the fix action please?
Click to expand...
I have been busy and haven't had a chance to order the parts.


#19

M

MParr

MParr said:
I have been busy and haven't had a chance to order the parts.
Click to expand...
UPDATE
The rich mixture problem continues.
On cold soak starts, it will often flood. I have ordered a All Carb Chinese knockoff from Amazon. It's one of the more expensive offerings. I plan on installing it tomorrow. I also plan on rebuilding the OE Nikki carburetor for backup.
I will give you all updates on this.


#20

S

slomo

MParr said:
the OE Nikki carburetor
Click to expand...
Now the truth comes out. Those Nikki's, I've had nothing but bad luck. Bought aftermarket and OEM rebuild kits. Those ultra small o-rings get poorly punched out and leak. Never could get them to work proper. Some guys love rebuilding them and have good luck. Trash can it went. Used a Walbro version for that Briggs engine I was working on. Worked like a charm. I know you are working on a Kawi engine.

Good luck with your carb. Let us know if you need more help.


#21

M

MParr

slomo said:
Now the truth comes out. Those Nikki's, I've had nothing but bad luck. Bought aftermarket and OEM rebuild kits. Those ultra small o-rings get poorly punched out and leak. Never could get them to work proper. Some guys love rebuilding them and have good luck. Trash can it went. Used a Walbro version for that Briggs engine I was working on. Worked like a charm. I know you are working on a Kawi engine.

Good luck with your carb. Let us know if you need more help.
Click to expand...
I wish that I could get a Walbro carburetor for this Kawasaki Mule. It's a 2019 Kawasaki Mule SX 4x2. I listed the engine above.
Here's the kit that I plan on ordering. It's made in Japan and should work well.


#22

S

slomo

That is WAY different than a Briggs Nikki. That looks to be a simple rebuild. Give it a shot. Not seeing any negatives as long as it fits what you have.


#23

M

MParr

slomo said:
That is WAY different than a Briggs Nikki. That looks to be a simple rebuild. Give it a shot. Not seeing any negatives as long as it fits what you have.
Click to expand...
I did notice that the main jet in the kit is quite a bit smaller than the OEM jet. This thing has had problems since new. It's just gotten worse over time. I'm thinking that a new main jet and needle will cure the problem.
Here's what I ordered. I see that Stens carries a similar product for about the same price.



#24

Scrubcadet10

Scrubcadet10

Does it still have the factory vacuum fuel pump?


#25

M

MParr

Scrubcadet10 said:
Does it still have the factory vacuum fuel pump?
Click to expand...
Yes. It seems to be working fine. It runs great after initial warm up.


#26

M

MParr

MParr said:
Yes. It seems to be working fine. It runs great after initial warm up.
Click to expand...
I think that I will pick up an OEM fuel pump tomorrow. I may as well replace it while I'm in there.


#27

Tiger Small Engine

Tiger Small Engine

slomo said:
Now the truth comes out. Those Nikki's, I've had nothing but bad luck. Bought aftermarket and OEM rebuild kits. Those ultra small o-rings get poorly punched out and leak. Never could get them to work proper. Some guys love rebuilding them and have good luck. Trash can it went. Used a Walbro version for that Briggs engine I was working on. Worked like a charm. I know you are working on a Kawi engine.

Good luck with your carb. Let us know if you need more help.
Click to expand...
A Nikki (single cylinder) carburetor is like a Kohler Courage (single cylinder) engine, problems. Nikki carburetors are prone to leaking and hydro locking the engine, more difficult to clean and rebuild, and just generally a pain. I have had good results with aftermarket Nikki carburetors when needed.


#28

S

slomo

Don't know for sure but I would guess at the Briggs Walbro might fit as well. ???? Or be close enough to easily adapt to.


#29

M

MParr

slomo said:
Don't know for sure but I would guess at the Briggs Walbro might fit as well. ???? Or be close enough to easily adapt to.
Click to expand...
The aftermarket carburetor and OEM fuel pump have been installed.
It's not the easiest job.
I finished the installation and get ready to adjust the idle. I cranked and cranked and cranked. I know that I had everything right. I looked down and saw my vise-grips clamping off the fuel line. Big dummy! After removing the vise-grips, it fired right up.
Time will tell if the Chinese carburetor cures the problem.


#30

M

MParr

I figured that had better move swiftly on the carburetor replacement. Over the past few mornings I have noticed raw gasoline coming from the tail pipe. My suspicion was confirmed. Gasoline was mixing with the crankcase oil. The air filter and air filter box were dry. I changed the oil and filter. It runs darn good now.


#31

S

slomo

MParr said:
I looked down and saw my vise-grips clamping off the fuel line.
Click to expand...
I have NEVER done that......... LOL LOL o_O


#32

S

slomo

MParr said:
It runs darn good now.
Click to expand...
Dur dunt ditl dunt dur dunt dityl dunt. My best Dukes of Hazard horn honk. LOL

Thanks for letting us know.


#33

M

MParr

slomo said:
I have NEVER done that......... LOL LOL o_O
Click to expand...
Come on, tell the truth. 😅


#34

Scrubcadet10

Scrubcadet10

MParr said:
Come on, tell the truth. 😅
Click to expand...
thats why i bought a set of the fuel line clamps that are BRIGHT ORANGE :ROFLMAO:


#35

M

MParr

Scrubcadet10 said:
thats why i bought a set of the fuel line clamps that are BRIGHT ORANGE :ROFLMAO:
Click to expand...
The dang thing was hiding from me.😅 I might have to visit my local Harbor Freight and get a couple.
I intend to add a shut off valve in the fuel line.
I was just out looking at the original carburetor. I didn't notice any obvious signs of a problem.
The overflow tube is clear.
The float needle looks good.
The float is good. The float pin is straight.
I'm not sure the thing is worth rebuilding. Stens has a direct replacement and the All Carb (from Amazon) are both under $50.
The All Carb is the one that I installed. It's working great.


#36

Scrubcadet10

Scrubcadet10

MParr said:
The dang thing was hiding from me.😅 I might have to visit my local Harbor Freight and get a couple.
I intend to add a shut off valve in the fuel line.
I was just out looking at the original carburetor. I didn't notice any obvious signs of a problem.
The overflow tube is clear.
The float needle looks good.
The float is good. The float pin is straight.
I'm not sure the thing is worth rebuilding. Stens has a direct replacement and the All Carb (from Amazon) are both under $50.
The All Carb is the one that I installed. It's working great.
Click to expand...
I've used the All Carb on a few engines where the customer didn't want pay for a OEM or rebuild kit, and they've worked great.


#37

M

MParr

Scrubcadet10 said:
I've used the All Carb on a few engines where the customer didn't want pay for a OEM or rebuild kit, and they've worked great.
Click to expand...
Those Shindy rebuild kits are around $25. However, the float and float pin aren't included.


Footer Links 1

Top