Jump to content

FCR 39MX install, using the TT KIT

Recommended Posts

Much has been written about the OEM Mikuni BSR36 carb, you can jet it, tune it, tweak it, but in the end, it’s still a CV carb, with limited potential. Used on on all S and SM model DRZ's. (plus late model E bikes in the US)
If your reading this now, you have already decide the extra HP and better throttle response of a well jetted FCR39 MX carb was worth the price. That’s the hard part.. What follows, is much easier. Installing the FCR on to a DRZ originally equipped with the Mikuni BSR36 is not hard. Though some general knowledge of motorcycles and Carbs specifically is important, with the right attitude and understanding your install will be full of stop and go as you research, learn, and ask questions. Anyone with decent mechanical ability and basic tools can perform this install.


The Thumper Talk Keihin FCR39 MX carb kitfits all DRZ's having a BSR36 carb, All S and SM models, and 2007 and later E model bikes.

The kit includes:
- 016-925 Keihin 39mm FCR MX Carb with choke (no TPS)
- 021-216 FCR Adapter 2 3/8", carb to S airboot
- 021-439 Adaptor O-Ring
- 017-262 EMN Needle
- 021-012 Airboot adapter bolts (2)
- P/N 13111-29F00 OEM Suzuki E Intake Manifold
- P/N 09402-58208 OEM Suzuki Clamp
- P/N 13685-29F00 OEM Suzuki Vacuum Port Nipple

Carb comes standard with the following:
- 200 Main Air Jet
- 160 Main Jet
- 45 Pilot Jet
- 100 Pliot Air Jet
- EMR Needle


Prepping the new Carb and bike for install

Remove and discard the plastic throttle wheel guard, it will interfere with fitment relevant to the frame, and really is not needed.

Move both upper motor mounts to the left side; this allows needed clearance for the throttle wheel
motor mount.jpg
The TPS connector will not be reused with the new FCR carb, you can follow the carb end up wiring to the connector and unplug it there. Use some dielectric silicone and tape to blank off the connector, you can cut the wires there, heat shrink or tape the ends, or simple stuff the carb end of the TPS and wiring harness up under the seat, zip tie it in place and leave it. Bottom line, it is not used for this install.

If using a vacuum operated fuel petcock like the OEM one found on the DRZ S or SM, you will need to install a vacuum nipple in the manifold. Luckily there is a spot just for this and an OEM part to install. It is P/N 13685-29F00 OEM Suzuki Vacuum Port Nipple and included in the TT Kit

Install the jetting required for your motor modification level and riding area. Provided are four common jetting setups. For many, that’s all they will need to do, for some, additional tuning will be required. Use what is here for a base, make a post as to what your bike is doing related to jetting you do not like, and let the experts help you through the tuning.
be descriptive, and specific.
Include your current motor and intake mods, jetting set up, altitude and temp where you ride. mods, jetting set up, altitude and temp where you ride.

Basic Jetting

TT FCRMX 39 air jets.jpg

sea level stock exhaust or "quite,96db,corked up etc aftermarket pipe", 3x3 -

155 main jet
200 main air jet
EMN needle
clip 3
45 pilot jet
2 turns fuel screw
o-ring mod

sea level,aftermarket pipe with open muffler-

160 main jet
200 main air jet
EMN needle
clip 3
45 pilot jet
2 turns fuel screw
o-ring mod

4000-600ft,stock exhaust or "quite,q,96db,corked up etc aftermarket pipe", 3x3 -

145 main jet
200 main air jet
EMP needle
clip 3
45 pilot jet
2 turns fuel screw
o-ring mod

4000-6000ft,aftermarket pipe with open muffler-

150 main jet
200 main air jet
EMP needle
clip 3
45 pilot jet
2 turns fuel screw
o-ring mod

In addition to the above or custom jetting, an extended adjustable fuel screw is highly recommended.
Merge Racing makes a very nice one. merge racing FuelMixtureScrew.jpg What I like most about it is the Injection molded knob.. stays cool when the engine is hot, for easy adjustments. And because of its T shape is easier to grab with gloved hands and make adjustments.
If not the Fuel screw from Merge, then any of the aftermarket screws not made from aluminum. Be very careful on the removal and install of the new fuel screw.. you have a small spring, washer and rubber O-ring that sits on the screw inside the body. One or more of these part sometimes remains in the body, and comes out haphazardly on the end of the old fuel screw. Very easy to lose one or more parts.

The Fuel needle clip position is counted from the top, flat end of the needle. The needle pictured is in clip 3 position.
clip 3 side view.jpg
clip 3 top view.jpg
Install tips

No need to buy new throttle cables, the stock S cables work fine.
Attach the throttle cables with the curved one on the bottom
cable set up.jpg

Hoses are routed like this
hose routing from top.jpg

hose routing.jpg


intake adapter IS too short



It’s really not too short. People say this all the time due to the physical measurement between old carb set up and FCRMX being different, the FCR setup is slightly shorter. The air boot is plenty long enough. The preferred technique is to put the carb in the boot first. Then pull it forward to the manifold.



  • Like 20
  • Helpful 1

Share this post

Link to post
Share on other sites
This topic is now closed to further replies.