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Discussion Starter · #1 ·
I bought my Z400 with the intent of riding well into my Senior years. I mostly ride in the twisties near Santa Cruz CA but have moved farther North so now forced to ride more freeway to get there. Just thought I'd share what my Z400 looks like, going on two years and a list of mods. Latest is a full Musarri Exhaust System. Vagabond Fender eliminator, Larger Kawasaki Screen, Sharai lithium battery, Spears Racing clutch springs, Norton Motorsports seat, 15 tooth front sprocket, Zeta bar risers (1'up, 1' back), Kawasakibrad.com evap and pair valve eliminated, 02 sensor elimination (ordered), Custom fork work and preload adjusters (this week), shorty levers (generic), Bar end mirrors (generic, some custom work)....and Grip Puppies. Upon installing the full exhaust I thought it would run like garbage without a proper flash however it now runs much smoother, quieter, and the temperature gauge runs much cooler. The CAT retained a lot of heat. Also it doesn't pop and crackle like when I had the CAT and Coffman's.
Kawasakibrad says his 02 elimination plug adds 3% more fuel to the mixture. I do not race just a old guy riding the canyons so I may avoid flashing the ecu.
Please post some of your photos, would like to see some Z400s!!
Tire Wheel Fuel tank Automotive fuel system Vehicle
 

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I bought my Z400 with the intent of riding well into my Senior years. I mostly ride in the twisties near Santa Cruz CA but have moved farther North so now forced to ride more freeway to get there. Just thought I'd share what my Z400 looks like, going on two years and a list of mods. Latest is a full Musarri Exhaust System. Vagabond Fender eliminator, Larger Kawasaki Screen, Sharai lithium battery, Spears Racing clutch springs, Norton Motorsports seat, 15 tooth front sprocket, Zeta bar risers (1'up, 1' back), Kawasakibrad.com evap and pair valve eliminated, 02 sensor elimination (ordered), Custom fork work and preload adjusters (this week), shorty levers (generic), Bar end mirrors (generic, some custom work)....and Grip Puppies. Upon installing the full exhaust I thought it would run like garbage without a proper flash however it now runs much smoother, quieter, and the temperature gauge runs much cooler. The CAT retained a lot of heat. Also it doesn't pop and crackle like when I had the CAT and Coffman's.
Kawasakibrad says his 02 elimination plug adds 3% more fuel to the mixture. I do not race just a old guy riding the canyons so I may avoid flashing the ecu.
Please post some of your photos, would like to see some Z400s!! View attachment 19159
Beautiful!

Interested in those mirrors. Any info would be helpful.
 

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Hey, bike looks awesome. Adding a full system will definitely make the engine run hotter because it further leans out the mixture so it must be an elusion. I can't stress how much better the engine will run with a proper ECU flash but that is obviously not a must have, but it certainly will actually allow the engine run a lot cooler, smother, and increase performance by improving the fuel maps.
 

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Discussion Starter · #4 ·
Beautiful!

Interested in those mirrors. Any info would be helpful.
I took a chance on an no name Chinese brand that turned out to be very good quality. Had to ream the mount holes bigger. A lot of fiddling with the view angle. Kawasaki used locktite on the barend weights so you you need a rattle gun to remove them, or the bolt could break. They were about $35.
 

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Discussion Starter · #5 ·
Hey, bike looks awesome. Adding a full system will definitely make the engine run hotter because it further leans out the mixture so it must be an elusion. I can't stress how much better the engine will run with a proper ECU flash but that is obviously not a must have, but it certainly will actually allow the engine run a lot cooler, smother, and increase performance by improving the fuel maps.
I've ridden it on two 150 mile canyon rides and the temp gauge is now always in the middle. I've got 5,500 miles on her, just relaying my observations. I fully intended to flash the ecu but its running so sweet right now. I'm in email contact with Kawasakibrad.com and purchased a 02 sensor eliminator plug. He told me his plug is programmed to deliver 3% more fuel. Used to get 60 mpg, the full exhaust dropped it to 57 mpg so it is using more fuel now.
 

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I've ridden it on two 150 mile canyon rides and the temp gauge is now always in the middle. I've got 5,500 miles on her, just relaying my observations. I fully intended to flash the ecu but its running so sweet right now. I'm in email contact with Kawasakibrad.com and purchased a 02 sensor eliminator plug. He told me his plug is programmed to deliver 3% more fuel. Used to get 60 mpg, the full exhaust dropped it to 57 mpg so it is using more fuel now.
It is physically impossible to add a full system and run cooler on the OEM tune, it just simply can't happen. The narrow band 02 can compensate for very small changes only like a slip-on but not a full system. Maybe someone else has different information.

Perhaps the OEM air filter element is able to restrict the air intake enough that it doesn't lean out the mixture more than a slip-on?

According to Norton the air box is a restriction which is why they recommend removing the snorkels and cutting open the box.
 

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It is physically impossible to add a full system and run cooler on the OEM tune, it just simply can't happen. The narrow band 02 can compensate for very small changes only like a slip-on but not a full system. Maybe someone else has different information.

Perhaps the OEM air filter element is able to restrict the air intake enough that it doesn't lean out the mixture more than a slip-on?

According to Norton the air box is a restriction which is why they recommend removing the snorkels and cutting open the box.
Flowing more exhaust doesn't necessarily mean more heat. Especially if that exhaust is cooler with slightly richened mixture.

A properly built O2 eliminator will fake a semi lean signal. The ECU and factory map will compensate by richening up a bit. Maybe 3-5% across the board. Since the ECU doesn't get any feedback but it's still within acceptable parameters it doesn't correct any further and just stays there. Key being acceptable parameters so it doesn't trigger a check engine light. 3-5% added fuel will make any engine run cooler.

Removing the PAIR valve and hose vent nipple thing on top of the valve cover flows more air between the valve cover an the tank. Not sure if there is a measurable effect. But flowing more outside air through that otherwise very hot spot cannot hurt.

How about that giant cat? It has a huge amount of thermal mass, get's really frickin hot, and holds that heat right up against the belly pan of the engine. Getting rid of that alone reduces engine temps which I think might be the main cause and effect we're seeing here.

The stock airboxes are very restrictive. But so is the stock exhaust. With a full exhaust we now change how the engine exhales, but it can't inhale much more than it was before. How much more are we actually flowing? Plus, flowing much more at 14.0:1 AFR (rough guestimate with O2 eliminator) vs less air 14:4:1 AFR (approximate stock value) will also be cooler.
 

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Discussion Starter · #11 ·
Hey Flash, where are you on the 02 dummy plug? Adds 3% huh?⁹
Will go for a proper canyon ride soon but installed it and removed the 02 sensor. Rode it around and did a short freeway ride. I need to do a real ride before I can decide if I like the feel. Will look for throttle response, feeling and milage. Got 60 mpg stock, 57 with full exhaust and with this 02 dummy plug added will probably get 56 mpg due to more fuel in the mixture. I get back about this.
 

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Discussion Starter · #14 ·
Thanks, keep us in the loop
🐉
Update: Stock ecu and the full Musarri exhaust with silencer installed, 02sensor removed and plugged, replaced with an kawasakibrad dummy plug. Rode 100 miles today with freeway up to 90, extreme twisty canyon roads and high speed coastal highway. The temperature gauge never rose above 4 bars, mostly at 3 bars. She just purred like a kitten at all rpm. Had professional suspension work done so I'm riding with more confidence in the tight stuff. 56.5 mpg, I don't ride at race pace. I'm very happy with my Z400, it's just a super little machine!
 

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Update: Stock ecu and the full Musarri exhaust with silencer installed, 02sensor removed and plugged, replaced with an kawasakibrad dummy plug. Rode 100 miles today with freeway up to 90, extreme twisty canyon roads and high speed coastal highway. The temperature gauge never rose above 4 bars, mostly at 3 bars. She just purred like a kitten at all rpm. Had professional suspension work done so I'm riding with more confidence in the tight stuff. 56.5 mpg, I don't ride at race pace. I'm very happy with my Z400, it's just a super little machine!
Did the Kawibrad plug help twitchy throttle?
 

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Pretty machine! I've never seen a white Z400. How many mile do you have and have you been able to tour on her?
Thanks! Sorry, I missed the updates to this thread. I have about 14000KM (8500mi) but I have to check the odometer, will update later because now it is under cover.

I have not used it for touring really. The longest ride was about 2 1/2 hours when we went for a short vacation last year. I look forward to the day when I can ride more. Right now I do about 45 minutes or 60 minutes a day, mostly for fun.

PS:

It has 13921 KM / 8650 mi.
 

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Discussion Starter · #17 ·
Did the Kawibrad plug help twitchy throttle?
The Z400 came alive when I removed the stock exhaust (the Cat / Coffman's) and installed the Musarri full exhaust system. It now feels like I don't have to pull the throttle grip as far to excellerate. The engine is running smoother and effortlessly. In my case the bike runs almost identical with the stock 02 sensor or with the 02 delete dummy plug. I may switch back and forth for more comparison. Haven't touched the airbox, still has the stock filter so that is a future project.
 

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Discussion Starter · #19 ·

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Dig your wind screen! I would like more protection on the freeway. Is the ride quieter? Does it buffet your helmet at high speeds? Is it adjustable? How is it mounted? Figured I ask all at once.
Mighty fine stable!
Its a Puig. 5022. I think. Ride is much more protected, very little buffeting. Wind shear hits at rhe top of the visor. Completely protects upper torso because its wider than most. Somewhat adjustable but not a lot. Rests on the top of the dash cowl with a neoprene strip for cushioning, and clamps to the bars. Very stable, been on the bike since it was 2 weeks old. Would put the same one on again.
🐉
 
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