FCR carb users jetting,intake?

[jays375]

Just curious to see what the jetting people are using with the FCR carbs on a 350X?Either the 37mm or 39mm.Also what intakes are being used.

[xrider]

Havent been able to get up to the garage to check mine out for you. Next time im up I will take a look.

[6speedthumper]

I am not running one on my X yet (hell bike isn't even running), but, I do have one on my BUILT 88 Warrior. And, I'm running a totally custom intake, no air box, k&n with outerwears, and my pilot is a 68, I forget the needle I have in it but it is on the 3rd notch from the bottom(there are 7 total), and the main I had to drill out larger then a 235. Hope this helps.

[Dirtcrasher]

Jay, You got a nice FCR carb from what I remember us talking about.

Mine is a 39MM and I will build my own intake, probably have to run a pod air filter but we will see what I can rig up as long as it looks and performs great. Maybe build my own airbox, IDK........

Jason Hall has a 41MM on his 350X and says "it loves it!!". I will be speaking to him soon so we will see what suggestions he has for intake solutions when I speak with him. If I could get a TIG for aluminum, there would be NO questions :D

[jays375]

Well things were good until I put the new larger exhaust on.You will be able to run the air box.TC racing told me no gain with a pod air filter.With the ported head and bigger exhaust it is fuel hungry.I am going to try to make a intake next week.Right now a 250x intake works.

[6speedthumper]

My X is not in front of me to check the size of the intake port is, but, I was able to use 1.5" pipe on my Warrior, ported it, and joined it to the carb with a 1 7/8" to 1.5" silicone reducer tube.

[Tecate performance]

Use a 300ex intake manifold on the head, it has a bigger carb flange opening than the 350x, and port match the I.D. what type FCR are you using, the original style or the MX series that came on the 02 up CRFs and 03 up YZFs? The orignal had the accel. pump linkage exposed and will take a different style pilot jet than the MX series. On my 350x 452/492/515 engine I ran a 41 FCR 400ex kit (original style) with 48-50 pilot, and 185-195 main jet. That's with a megacycle 144-25 cam, powroll exhaust (300ex chassis), and 400ex airboot/filter in 300ex airbox no lid.

[Dirtcrasher]

Just curious to see what the jetting people are using with the FCR carbs on a 350X?Either the 37mm or 39mm.Also what intakes are being used.

Jay was the one you got with the nice bowl and air screw a 39mm??

I grabbed a nice 39MM cheap and plan to match (some type of.....) intake to it. At that time, I am also sending the head out to be ported; So, I want it all to flow.

I said a "pod filter" because I have no clue how I will fit this all up but rest assured, it will be done and done well..........

I wonder how anyone could say a pod filter would not be a gain?? It allows ALLOT more air so allot more fuel as well, NO??. TC racings comment has me a bit confused??

I'm all busted up so I am sending the head and carb to be matched (39mm) and I will probably send out my newest crate 350X rockers to be hardwelded just to make sure to avoid wear even though they are NOS rockers. I'll be curious to see the wear after a hundred hours of beating the snot out of it, enough to get me nearly killed :lol: I want to toss in my Barnett clutch kit too as it is just a tad bit lazy and I may as well do it. But that crate clutch has worked just fine for all those hours :beer

[6speedthumper]

Jay was the one you got with the nice bowl and air screw a 39mm??

I grabbed a nice 39MM cheap and plan to match (some type of.....) intake to it. At that time, I am also sending the head out to be ported; So, I want it all to flow.

I said a "pod filter" because I have no clue how I will fit this all up but rest assured, it will be done and done well..........

I wonder how anyone could say a pod filter would not be a gain?? It allows ALLOT more air so allot more fuel as well, NO??. TC racings comment has me a bit confused??

I'm all busted up so I am sending the head and carb to be matched (39mm) and I will probably send out my newest crate 350X rockers to be hardwelded just to make sure to avoid wear even though they are NOS rockers. I'll be curious to see the wear after a hundred hours of beating the snot out of it, enough to get me nearly killed :lol: I want to toss in my Barnett clutch kit too as it is just a tad bit lazy and I may as well do it. But that crate clutch has worked just fine for all those hours :beer


That sounds damn noice! ^^^ I'm going to use a 36x38 Edel on mine, but, I'm still so freakin tempted to put a 39mm on there. I know how it performs, and man, it can't be beat...

[jays375]

First FCR was only a 37mm.It won't take much to fit up the stock air box.You might have to raise the rear tank mounts to clear.The steel tank would but the Clarke wouldn't.On the rockers yes on the hard face.Now the way TC explained it was the hole going into the carb is only so big.Which makes sense if you think about it.You should try to hunt up a XR 400 head pipe.Better choice than the 400ex,bigger.Kasey used one on his last project.You will be very pleased with the end results with the modifications.Mine runs really well.

[Jason Hall]

I have a 05 CRF450 carb on my 350x. I ported the head to accept the bigger carb and built a steel intake. It was pretty simple. I used a short collar to adapt to the stock intake boot between the airbox and carb. With mine I changed nothing as far as jetting other than a Bigger main jet. The secret is how you shape the intake port, and how much you open up the exhaust. One thing I will tell about the intake port is this!! Velocity is your friend when using a FCR.. The FCR Loves a tapered intake port, as that is what most all modern bikes have. Over the years most all manufacture's have reduced the size of there intake ports. This is no secret, so if you hog out your intake on your 350x you will have a hell of a time jetting a modern carb.

[6speedthumper]

I have a 05 CRF450 carb on my 350x. I ported the head to accept the bigger carb and built a steel intake. It was pretty simple. I used a short collar to adapt to the stock intake boot between the airbox and carb. With mine I changed nothing as far as jetting other than a Bigger main jet. The secret is how you shape the intake port, and how much you open up the exhaust. One thing I will tell about the intake port is this!! Velocity is your friend when using a FCR.. The FCR Loves a tapered intake port, as that is what most all modern bikes have. Over the years most all manufacture's have reduced the size of there intake ports. This is no secret, so if you hog out your intake on your 350x you will have a hell of a time jetting a modern carb.


Yes it does^^^. My bike sounds like it has a small super charger on it because of all the air it pulls in. Whistles like crazy.

[Dirtcrasher]

[QUOTE=jays375;1263399You should try to hunt up a XR 400 head pipe.[/QUOTE]

I got that covered :D

http://i257.photobucket.com/albums/hh220/Dirtcrasher/charles060_zps1d274bca.jpg (http://s257.photobucket.com/user/Dirtcrasher/media/charles060_zps1d274bca.jpg.html)

http://i257.photobucket.com/albums/hh220/Dirtcrasher/charles062_zpsc4f3735e.jpg (http://s257.photobucket.com/user/Dirtcrasher/media/charles062_zpsc4f3735e.jpg.html)

http://i257.photobucket.com/albums/hh220/Dirtcrasher/charles064_zpsac43f1d6.jpg (http://s257.photobucket.com/user/Dirtcrasher/media/charles064_zpsac43f1d6.jpg.html)

http://i257.photobucket.com/albums/hh220/Dirtcrasher/charles065_zps93db87cb.jpg (http://s257.photobucket.com/user/Dirtcrasher/media/charles065_zps93db87cb.jpg.html)

Jason will have a package on the way soon (gotta call you bud). I don't like the inner welds of the XR pipe. I'd like to see the collars welded on the outside and the inside smoothed out and enlargened......