MIKUNI BRS36 / BSR36
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OEM REPLACEMENT
 
Achat Buggy 500 Carburetor
Achat-buggy 500 Carburetor
Adventure 500 Carburetor
Allroad 500 Carburetor
Armadillo Carburetor
BSR36-89 Carburetor
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Carter Gauche 500 Carburetor
CF Motori Carburetor
CF Motori Carburetor
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CF500 Terraforest Carburetor
CFATV 500 Carburetor
CFEngine Carburetor
CFMoto 500
CM Buggy 500 Carburetor
COG 500 Carburetor
DESPIECE 500 Carburetor
Diamo 500 Carburetor
Dominator 500 Carburetor
DRZ400 Carburetor
DRZ400 Craburetor
E-Pood 500 Carburetor
E-КарбюраторPo 500
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G-Force 500 Carburetor1
Ginomotor 500 Carburetor
goes 500 Carburetor
Goes 520Max Carburetor
Grizzley 500 Carburetor
Hadaju FK500 Carburetor
Hadaju-buggy-fk500 Carburetor
HSUN Carburetor
Jocsports 500 Carburetor
Kaasutin 500 Carburetor
Karburaator Mikuni 
Klung 500cc Carburetor
LK500 Carburetor
LTF500 Carburetor
Mikuni 36mm Carburetor
Mikuni BRS 36 Carburetor
Mikuni Carburetor 500 cc
Moose 500 Carburetor
Moottori 500 Carburetor
OX500-100000 Carburetor
OXOKART 500 Carburetor
Rancher 500 Carburetor
Renli 500 Carburetor
Renli Buggy 500 Carburetor
Ricambio 500SP Carburetor
Roketa UV-03A Carburetor
Suzuki 500 quadrunne
Suzuki DR350 Carburetor
Suzuki DRZ400 Carburetor
SUZUKI GSXR1100 carburetor
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Swat 500 Carburetor
Terracross 500 Carburetor
Titan 500 Carburetorburetor
VCarbu CF500 Carburetor
Vergaser 500 Carburetor
XY500 Carburetor
Карбюратор 500 Carburetor
Карбюратор в сборе 500
квадроциклу 500 Carburetor
Наличие 500 Carburetor

TUNING

This is a step-by-step procedure for re-jetting a stock Mikuni BSR36 Carburetor

Mikuni BSR or BRS series carburetors are remarkably versatile instruments. The standard tuning seldom needs more than small adjustments to accommodate a wide range of engine set-ups. One of the more common required changes is the main jet size.

Aftermarket exhausts have a wide range of flow volumes and the best main jet size is closely associated with exhaust flow. Thus, it is often necessary to replace the standard main jet with a different size to accommodate the wide range of exhaust designs on the market.


Keep in mind that the main jet does not affect mixtures until approximately 3/4 throttle. Below that throttle setting, specifically between 1/4 and 3/4 throttle, air/fuel mixtures are controlled by the jet needle and needle jet.



Step 1
The first step before you even begin to tear into the carb is to give your machine a good cleaning. Do not run the risk of contaminating the carburetor or engine while you are working on it.

Step 2
Next you must be able to get at the carburetor to work on it.

Step 3
Drain the carb bowl. Once the fuel has been drained unhook the fuel line and vent line from the carb, unhook the choke cable and throttle cable. Then loosen the carb boot clamps and remove the carburetor.

 

mikuni brs36

 


CHANGING THE MAIN JET


Step 4
The main jet controls the fuel flow from ¾ throttle to full throttle. A larger numerical main jet increases the fuel flow from ¾ and beyond.

To change the main jet turn the carb upside down and remove the idle mount screw on the carb bowl and then remove the 4 screws on the bottom of the carb (see picture below). These screws are very tight so make sure you have a good screw driver or impact driver to remove them, or they will strip.
If you round out the head of the screw, don’t worry just take a dremel tool and cut a slot in the screw to remove it with a flat head screw driver. We recommend buying new allen head screws to replace the old ones.

Step 5
With the carb bowl off you now have access to the main jet (along with the starter jet and pilot jet). With a wrench hold the Main jet holder and unscrew the main jet with a flat head screw driver and replace with correct jet. That’s all there is to it so now you can fasten the carb bowl back on.
ADJUSTING NEEDLE JET CLIP


Step 6
The needle jet controls the amount of fuel from ¼ to ¾ throttle positions. By moving the e-clip up you lean out the mixture and lower the e-clip richens the mixture.

To get to the needle assembly remove the two screws holding the diaphragm cover on and beware of the large spring underneath it. There is a very small o ring on the side of the diaphragm cover that you need to be careful not to lose.

Step 7
With the cover off gently pull up on the rubber diaphragm and remove the slide. With the slide out of the carb take a pair of (needle nose) pliers and pull on the needle holder to take out the needle assembly. There is a tiny spring under the needle holder that can pop out so keep an eye open for that.

Step 8
Now that the needle is out you can make the adjustments needed. Just take note of the placement and order of the washers, spring and spacer are in for when it’s time to re install it.

Step 9
When putting the needle back in make sure it clicks into place in the diaphragm. Then put the diaphragm and slide back into the carb and put the diaphragm cover back on, be sure that the rubber seal is positioned right and that the rubber o-ring is in place.

ADJUSTING THE PILOT SCREW


Step 10
The Pilot screw tunes the low end circuit of the carb from idle to ¼ throttle. Turning the screw out richens the mixture and turning it in cuts back the fuel flow, making it leaner.

The Pilot screw is located under a brass plug that needs to be drilled out and then take a self tapping screw and thread into the hole. With a pair of pliers pull the screw out which will bring the brass plug out with it. Now make the adjustments.

Step 11
Now comes the fun part and seeing if your new jetting setup works properly. Install a new spark plug to do a plug check.

Step 12
With the ATV up to operating temperature do a run at full throttle and then hit the kill switch and cost to a stop. Remove the plug and take a look at it, the porcelain on the plug should be a nice tan color, if not then some more tuning will be needed. A white plug indicates it being lean. If yu run too lean you can do a lot of damage to your bike. 
If the plug is black or oily  you are too rich which will lead to fouled plugs, dark exhaust and hard starting. Remember that this was done at (WOT) so is verifying your main jet.  Adjust the size of your main jet up or down until you get the right results.

Step 13
If that looks good then check your midrange (needle jet clip) and work your way down to idle making proper adjustments.

That’s all there is to it, and it’s pretty easy to do, in fact the hardest job is just getting the carburetor out so you can work on it easily and getting it tuned properly.