Anyone falmiliar with both? What is the diferance between the two?

What is the "BSR3b" that is always stated with the Z carb?

Is there a big diferance in the actual throtle vs thumb lever ratio?

I am trying to figure out why the throtle on the EX delivers such smother control over the Z. If I am rideing the EX over several rough ruts, I don't make any adjustments or anything, just bounce right through. On the Z, it is imposible for me to keep a steady throtle position, you can even here it, it sounds like I am bliping the gass through the rough stuff. Sometimes this can get a little out of hand, depending on the terain.

Any coments(other than"learn to ride&quot would be appreciated!

Later...

 

The biggest difference between the two is that with the Suzuki carb you don't have a direct connection between your thumb and the throttle.

The Mikuni BSR is a CV carb which means that it incorporates both a slide and butterfly. The butterfly is operated by the thumb throttle, the slide is operated by only engine vacuum. So, when you hammer the throttle you don't actually get full throttle until the engine vacuum lifts the slide.

On the 400EX, it has both a slide and butterfly as well, however, both are directly actuated by the thumb throttle.

From what I hear, upgrading to a 400EX carb makes a nice improvement in bottom end as well as power across the board.

Why Suzuki chose to use a CV carb is beyond me.... However, it's a problem that's easily corrected.

 

I'm not knocking the Z, but I think you nailed it for me! Thanks

I couldn't figure it out, this makes sence, it almost feels eratic at times, I have been trying to blame it on myself, thinking I would get the feel for it but after 20 + hrs, I have only managed to strengthen my fore arms from death griping it in the rough stuff trying to keep the throtle seady.

Does anyone know exactly what is needed for this carb swap? Like, intake, air filter Boots, cables? I take it there is physically enough room, the EX carb looks twice as big as the Z's.

1986atc250r, thanks for the heads-up,

any other coments?

Later...

 

There's a guy on the LTZ e-mail group group named Dana that has done this swap and has even dyno'd the difference - you may want to talk with him...

 

It will cost a little more, but consider this swap instead. Buy an intake for a new DRZ400 and the carb off of the DRZ will work. It uses a Keihin FCR 39mm (the best carb available in my opinion). You can buy the FCR from shops such as FTZ, suzuki dealer, or from sudco. I am told that the airbox to carb boot from the DRZ will work on the LTZ w/ the FCR, but I don't know for sure.

 

The FCR is a great carb, I use one on my 400EX...

However, minimum cost on an FCR will be around $400 (unless you get a great deal on a used one). You can commonly pick up EX carbs for under $100.

Depends on what you're looking to do. The EX carb is a great solution as an interim carb before you do big mods or a carb for someone who's just looking for better response and a tad more power.

 

I see from your sig you have a 300EX.
One thing to keep in mind is that the Z400 is making twice the power of a 300EX. Slight throttle changes have little affect with a 300EX motor, and have a huge affect on a Z400 motor with lots of power everywhere in the powerband.
A slightly better carb would actually make the throttle changes even more noticable.
The Honda EX motors are tuned for more bottom end, and when stock do not keep pullin in the upper revs like the Z400.
Just a thought. Hope ya get that beast under control[img]i/expressions/face-icon-small-smile.gif[/img]

 

Hey guyes, great info, every once in a great while this internet stuff is worth it's weight in gold.

So the EX carb would not be a limitation on the Z unless I want to do serious mods, I would expect the EX carb on the Z could handle an exhaust and air filter mod? I will reserch the info you'all provided me, again thanks!!!

Megacrash, I really do wish the Z was that much of a beast! If it had another 1/3 more hp you couldn't beat the smile off my face. I sold the 300ex, and had the chance to spend some time on the 400EX, it is a great quad, very capeable. I got the Z for the revier motor, liquid cooling, and reverse. I am very pleased with the Z, if I am hammering it through the rough or WOT up huge hills it's awesome. But when goeing through down right nasty rough areas, it gets chalenging due to the way the carb reacts to slight "uncontrolable" movement of the thumb. I consider myself the average weekend warrior, very seldom do I cull a trail or hill and rarelly do I get the priveledge to watch riders take on areas I don't do(except for mudd). I'm haveing a hard time trying to convince myself that it is my inabilities, it's hard to be humble, but it is possible. Don't take my word for it, try it, take the Z at a steady pace in 1st gear and hit a couple rocks\ruts and see if you can feel\hear the motor respond to your natural body english, now do it on a 400EX and notice the differance. If you don't notice the differance, I'll shut my mouth cuz it's just me!

Sorry so long, I get into this stuff sometimes, and my typing is rapidly improveing, now if my spelling would keep up....

Good coments guyes,
Later...

 

They used the CV carb to pass emissions for a green sticker. With a normal carb and different exhaust we would be parking our quads for the summer.

 

I believe Dana tested around a minimum of 1hp gain across the board. The big news was the "mush" in the bottom end disappeared.

I personally also like the direct response of a "real" carb vs a CV carb.

It sounds like the basic mods you're wanting to do would be complimented very well by the 400EX carb.

WP - I keep forgetting about you commies over there in the People's Republic of Kalifornia.... So you guys are responsible for this, eh....