Only the mid body gasket has 3 different versions. If you have the same model FCR MX in the video (with removable bell at 10:00 with 2 screws) you need the gasket kit we used in the video (all balls kit 26-1511 it also comes with the removable bell’s gasket). If you have the other two versions of the FCR 39 MX (both without removable bell) you can buy the mid body gasket kit that has both gaskets in it (I do not have a part number for that but most online stores have that kit if you see 2 big mid body gaskets in the photo thats it). That way you can use the one that has the same shape with yours. Or you can compare the photos with your old gasket and buy the one you need (all balls 26-1510 and 26-1512) these two gaskets look like they have the same shape but they do not. If you compare them from the same photo angle you will see the difference. Also we will make a new rebuild video with a non-removable bell FCR MX to show the difference in mid body gaskets. I hope this helps you, thank you for watching.

@@archura.industries wow thank you this kind of support is rediculess. You defenetly deserve more subscribers. keep up the good work 🤙👍

@@archura.industries sitting here trying to understand this stuff, I realized today my Yamaha YZ450 needs this to be done. ( I am pretty sure it is the same Carb.) I dont have the extra cash for someone to do it for me, im going to give it a shot because of this video. thank you

Yes, you can remove and install the carb like that easily. Since we rebuilt the whole engine and painted the frame carb was already out. Thanks for watching.

Glad you liked it!

Thank you sir!

You are welcome! Thanks for watching.

Thanks for your comment. We bought an ultrasonic cleaner after this video and it made cleaning parts super easy.

Glad it helped!

@@archura.industries oh it helped. without it my carb would still be in a thousand pieces!

Thanks!

You should google “fcr 39 mx” and look at some pictures.

You can’t order any body part separately.

If you are saying that choke is not staying on (pulled) and springing back in than you have to replace your choke.

They are just brass tubes for venting. I don’t think they have a specific name. Thank you for watching :)

Keihin says that you don’t have to take the mid body off. They also do not sell these gaskets you can only buy them as aftermarket. However this carb is old (18 years old) and have an unkown history. Also as stated in the video, strong chemicals used to clean carbs can cause gaskets to go bad. Glad you liked the video!

Hi, If I understood you correctly; the “pilot screw” also known as fuel screw is for adjusting idle fuel mixture not the idle speed. After adjusting the fuel mixture you can use that ribbed knob to adjust idle speed. That ribbed knob changes how much throttle stays open when the throttle is closed. So when you turn the knob right it pushes on the throttle plate like you are giving it a little twist fromt the throttle tube and this brings up the rpms.

Hi, I did some research but i couldn't find anything useful. It depends on so many variables like altitude and other bike mods. I would recommend you to post your question on a forum like thumpertalk. Have a nice one.

It should rotate thats ok. Replacing the o-rings should fix said leak. I tried to measure it for you it looks like o-ring inner diameter is 5.70mm and thickness is 1.30mm maybe you can find something close to these dimensions. Also make sure you buy the fuel resistant stuff. Regular o-rings may leak after sometime but can be used if have to. Hope this helps, take care.

If you can check the my reply to the pinned comment I talked about all the kits aviable and how to choose the right one. Thanks for watching.

It was in the rebuild kit All Balls 26-1521. But some FCR MX carbs have a different type press-fit float valve seat and to my knowledge its not possible to replace them.

Yes, it should be. Even though they have some small differences, all FCR MX carbs have the same design.

Hi, yes it does sound like its because of your carb, you should try to fully rebuild it like you see in our video. You also may have a leak on your intake manifold (between carb and engine) you might want to replace the intake boot if it has cracks. If doing all this does not fix the issue it might be because your carb's body is worn out. We will make a video about how to restore the carb body as well.

Hi, we used the cheapest one we could find. Gasoline quickly dissolves any-ish grease (except for silicone grease don't use that). I think we used white calcium grease, just don't use too much and you will be fine.

@@archura.industries thanks man

We will make a video on how to restore the FCR slide, but your problem sounds like either your carb body is worn or slide's wheel bearings are shot.

Hi, first warm up your engine so it idles without cutting out. Slowly turn the fuel screw in that will make the RPMs drop and stop turning it just before it dies. Then start turning it back out and stop when engine hits peak RPM. If your engine is still running bad you might need to change your pilot jet with a smaller or bigger one. (smaller one if your engine is too rich at idle, bigger one if its lean) If its still not working you should replace the mid body gaskets. If its still not running good there might be a leak from the slide and vacuum plate if your vacuum plate is worn replace it also check its gasket 9:00 . If your carriage still has too much front back play after replacing the worn vacuum plate your carb body is worn out and i will make a video for how to fix that. I hope this helps.

This carburetor is from a KTM 525 EXC and the main jet is 178, pilot jet is 42.

Did you check it if the threads are dirty, blocked or damaged? Maybe something is blocking it like the old o-ring or washer.

Hi, if you are talking about the air mixture screw; OEM Keihin part number is 1014-004-2002 for CR39 and I dont think that CR39 has anything in common with FCR39.

@@archura.industries aight, thank you!

Rebuild kits are from All Balls Racing. If you know which bike is your carburetor is from you can order it from their website or you can find the part number from their website and search it on ebay/amazon.

I thought there is nothing inside it*

You should probably replace the mid gaskets too. Your problem also can be the slide, did you replace the vacuum plate(and its gasket)? Sometimes carburetor is really worn and even replacing the vacuum plate is not good enough. If you did replace it make sure its is installed correctly. Make sure you buy the right mid body gaskets if you know what bike your fcr is from that can help or you can just open the mid body and take photos of the main gasket and compare it with what you are buying.

KTM 525 EXC

If you are planning to connect TPS back you should leave it on. But make sure you dry it completly. If you remove it you have to calibrate it using a multimeter. If you decide to remove it mark position of the sensor with a pen that way its easier to calibrate. But you do not have to connect the TPS it should not effect bikes performance.

Hi I really do not know who sells the oem AP jet but Athena has a dual squirt AP jet for better throttle response it is expensive but maybe you can buy that? I think its called “Athena dual spray venturi jet kit” its 90-80$ at amazon/ebay. Athena kit also comes with midbody gaskets for the newer non removable bell fcrs. If you have the first gen FCR MX like in the video you need to buy midbody gasket for that separetely. For the oem AP jet you can maybe ask jets R us.

@@archura.industries thanks I ended up actually calling the company that builds the face carbs and they were able to send me one for 25 after shipping thanks for getting back to me tho

No, just gaskets.

@@archura.industries I'll try it

We did use brass brush. It didnt even scratch the body. (Brush is really soft it doesnt even hurt my hands). Soda blasting media can dissolve in water so tiny holes are not a problem if you put the carb in warm water for some time after blasting. Soda blasting is a widely used technic when rebuilding carbs. Thank you for your comment!

No, it is not. Not every FCR is the same. This one has the choke on that hole. Other hole is blocked and this is a oem stock carb. It came with the choke in that hole. But I know most FCRs have their choke in the other holes Thanks for your concern and thanks for watching!

Lol because we decided to make a video after… But we will make a new FCR video and it won’t be broken down already :)