DRZ400SM Carb Suggestions

Ok... as i sit her impatiently waiting for my DRZ400SM to show up... I have been doing some research on the DRZ E & S Models... It's seems like allot of folks have swapped out 36mm Mikuni for the 39mm FCR carb - which appears to be the big difference between the two...

So, my questions are as follows

What is the best source for getting the fcr - I have seen many different prices listed in different folk's "my garage"

Does anyone have dyno results for an S with the mikuni and with the FCR.. and or results from the Stock S, before and after a jet kit installation.. I am trying to guage the power increase vs. the overall price of both to see what is worth doing...

Exhaust - what have folks seen the best results with so far....



I bought mine off a guy from E-bay. I came off a 99 YZ400F By for the best mod you can do for that bike...

I have both an E and S model. My S has an FCR and Full Exhaust system and has the E cylinder base gasket for slightly higher compression. The E is totally stock. Each bike has a different power curve but I am positive the E still has more power thanks to its more aggresive cams.

S stock is somewhere around 33HP peak the E is around 41HP peak. You wont even get close to 40 with the S unless you get some better cams and the FCR.

If you want to get the most out of your new SM you will need.....

1. FCR39 and all the required parts for the conversion

2. E base gasket (you will need a new headgasket and rings also while you do it)

3. Full Yosh or Muzzy SS Exhaust

4. Hotcams either intake only or both intake and exhaust

5. JD Jet kit is great for smooth throttle response

Its about $1200 worth of stuff probably but like night and day difference. The FCR is the biggest improvement. The others are gonna make a big noticable difference too. If you want to tack another $450 to the pricetag get an MT 436 kit and it should get you a lot further. :)

Here is a nice carb but its missing the intake bell ($40 new)


If you buy new, go to carbpartswarehouse.com or Sudco. Expect to drop around $525 for everything.

As mentioned above, this is the single best mod to make to your bike...PERIOD.

Followed by an exhaust and opening the airbox. I do not know what it does for power, but I can say what it does for the power delivery not to mention safety of the bike. -The bike used to bog after hard landings at the MX track (with 17s mounted) due to vacuum slide. The FCR is mechanical slide, so no such issue.

Furthermore, the stock carb feels like it is controlled by a rubberband, while the FCR yanks the bike alive with instant throttle response and power delivery that is best described as urgent. Of course, you will very likely be cussing everyone up while installing the carb, but once done you will be very happy that you did it. (Make sure to get the Scotts fuel screw)


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