Well I couldn't wait to purchase an exhaust, so I decided to rejet, remove the snorkel and the air box lid on the new ride. I wanted to see how much of a performance difference it would make.

First off, to change the main jet only takes five to seven minutes and you don't need to remove the tank. Simply loosen the boot clamps, remove the snorkel, and rotate the carb to the left opposite the exhaust side. Remove the four small phillips heads on the bottom and that's it. The main jet in my quad had a #125, stock. The jets are the same as a raptor. After several test runs with different mains I ended up running a #145. This made a big difference over stock and I feel it will run neck and neck with a bone stock raptor. I should know I used to own one. I performed four jetting changes with test runs in under an hour. Again, very simple to change the jet. This quad will perform great with just an aftermarket exhaust and filter. It should have all the power you need for the track or woods.

Just thought I would keep everyone informed of my findings.

 

I wish it was only so easy for me [img]i/expressions/face-icon-small-sad.gif[/img] This may sound silly but what about using a 400ex pipe on the z400 , are the headers compatable , is it possible ? If so what kind are you going to run ? Just curious on what makes the other machines "tick"

 

I'd just like to chime in and say: I truly, deeply despise you.. While your already jetting and tinkering around, The rest of us are patiently waiting with our thumbs up our- well, you get the point.. [img]i/expressions/face-icon-small-smile.gif[/img]

 

it is not possible michael, aside from the different dimensions, the 400ex has a dual exhaust port head with dual header pipes, the z400 has a single port head with a single head pipe.

 

buddah,Did you try a 150 main?Also,most people are getting even better results from bumping the pilot jet up to a 27.5.The good part about the z400 is it's been in the bike for a couple of years and there's a lot of information/mods to be found on them...I still can't understand why Suzuki didn't go with the Keihin FCR39.[img]i/expressions/face-icon-small-confused.gif[/img]

 

Thanks for the info. What exhaust are you thinking of trying?

Whats your altitude there in Utah?

A coworker of mine hopefully picks up his z400 this week, then it's off t the sandrags this Saturday......

 

I know you didnt just ask if a 400ex pipe would work.. Thats funny!!! PUT DOWN THE CRACK PIPE..


RoostKing...

 

buddah,

Any chance you are going to put the bike on a dyno soon?

I can believe it should keep up with a stock Raptor by rejetting. A stock Raptor is about 36 hp and you probably gained a few from opening the airbox and rejetting plus the difference in weight. The big question is how it will respond to an unrestricted exhaust.

Keep us posted.

/NotuRaptor

 

The altitude here in Utah is 4500 ft. elevation. I haven't tried a #150 main yet, but I'll install one this weekend and keep you posted. I do not have access to a dyno so I can't give you any horsepower numbers. Sorry about that.

As far as exhaust brands, I'm considering a Yoshimura, DMC, Muzzy, or HMF. Yoshimura and Suzuki go together like peanut butter and jelly so I'm leaning towards them. I've tried the others in the past and they perform well, we'll see. I really need to get some aftermarket shocks first, because I like to jump and ride the tracks more. We all know stock suspension doesn't compare to the aftermarket. Another thing, the plastic fasteners for the plastic are cool. Just pop them in the middle and they come right out. Much better fasteners than my raptor had.

 

buddah, you should look into yoshimura's cams/valvesprings/titanium retainers/cdi box combo kit, it is a very popular modification to do on the drz bike and it makes it pull on the midrange and topend like a yz426. i know that thumperracing sells them also and it will work with the quad motor.