FCR-MX question

[Rayphantom]

I had a 39mm FCR-MX carb installed on my DRZ-400s and whenever i give it about quarter throttle the carburetor makes a sound like its pulling in air, is that normal with these carburetors? Am i depriving it of air? is there some adjustment im supposed to make on the carb to allow it to pull more air? Id hate to not use this carb to its full potential

[Qqqqqqqqqqqq]

The motor pulls in the air , it passes through the FCR which blends fuel as the air passes through it .

I would say the FCR is doing it's job

Post your elevation and jetting specs with any motor mods

[quick221680]

is it like a whistle or hiss kind of sound? cause when i first put mine on i noticed it too. now i dont hear it, idk if i just got used to it or if it went away or what, but i put up a post about it and everyone said that it was normal.

[Craigo]

I had a 39mm FCR-MX carb installed on my DRZ-400s and whenever i give it about quarter throttle the carburetor makes a sound like its pulling in air, is that normal with these carburetors? Am i depriving it of air? is there some adjustment im supposed to make on the carb to allow it to pull more air? Id hate to not use this carb to its full potential

It's called induction noise.....so how is it running?...

[seemus]

It's called induction noise.....so how is it running?...

And it sounds awesome ?

[Rayphantom]

thanks for the answers you guys, i dont have a problem with it and its running fine as far as i know, i was just concerned cuz the stock one didnt make that noise, so i guess i was worried for no reason, you guys are awesome

[Romie]

just curious if the induction sound is actually the carb or because of the 3x3 mod, I'm thinking 3x3 mod. I think it sounds awesome reminds me of a boosted car with an open air filter.

[Craigo]

the sound is from the carb, it gets amplified by the air box opening..Try taking your bike for a short spin with the airbox side cover removed, sounds even sweeter..

[Rayphantom]

just curious if the induction sound is actually the carb or because of the 3x3 mod, I'm thinking 3x3 mod. I think it sounds awesome reminds me of a boosted car with an open air filter.

i actually ended up not doing the 3x3 mod i was afraid of having sand and dirt going in the airbox, i used a 1" hole saw to make holes at the top and the right side of the airbox and stuck filtered plugs in them, its not going to completely block out the elements but it'll help a bit, ?

[Rayphantom]

the sound is from the carb, it gets amplified by the air box opening..Try taking your bike for a short spin with the airbox side cover removed, sounds even sweeter..

hahah yea it does, i actually did do that to see if it'll help it but it ended up sounding the same if not louder

[Wild Ride]

hahah yea it does, i actually did do that to see if it'll help it but it ended up sounding the same if not louder

Of cause it would be louder if the airbox door was off....there is less to diffuse the sound waves, like opening your front door to shoot at the neighbours,compared to having it closed

edit....I meant shout,not shoot...

Edited September 20, 2012 by Wild Ride

[Craigo]

i actually ended up not doing the 3x3 mod i was afraid of having sand and dirt going in the airbox, i used a 1" hole saw to make holes at the top and the right side of the airbox and stuck filtered plugs in them, its not going to completely block out the elements but it'll help a bit, ?

Got pics

[Rayphantom]

Got pics

sure thing

Edited September 21, 2012 by Rayphantom

[Rayphantom]

the only reason it doesn't have more plugs is because i ran out ?

[Rayphantom]

Of cause it would be louder if the airbox door was off....there is less to diffuse the sound waves, like opening your front door to shoot at the neighbours,compared to having it closed

edit....I meant shout,not shoot...

yea i suppose it would sound louder if it came from the air box, but the noise im referring to is coming from the carb itself, like before it was jetted the air box would make a suction noise and after it was jetted it stop making that noise and ran a

lot better

[Wild Ride]

yea i suppose it would sound louder if it came from the air box, but the noise im referring to is coming from the carb itself, like before it was jetted the air box would make a suction noise and after it was jetted it stop making that noise and ran a

lot better

Sorry I am no expert here , I don't understand why that would be..My ex is a bike mechanic used to tell me lots of stuff .but never heard of what you are saying.

some of the experienced guys on here may be able to explain.

Lisa.

[Mad Dogg W]

Of cause it would be louder if the airbox door was off....there is less to diffuse the sound waves, like opening your front door to shoot at the neighbours,compared to having it closed

edit....I meant shout,not shoot...

The other problem is that it is very hard to sight them in with the door closed [not to mention the horrible mess it makes of your door]

[Craigo]

sure thing

If it's running ok it's only by luck...Having all those filtered holes could have made it a jetting nightmare...

Edited September 21, 2012 by CraigoDRZ485sm

[Qqqqqqqqqqqq]

i actually ended up not doing the 3x3 mod i was afraid of having sand and dirt going in the airbox, i used a 1" hole saw to make holes at the top and the right side of the airbox and stuck filtered plugs in them, its not going to completely block out the elements but it'll help a bit, ?

It's your bike and your way ... No need to be concerned over dirt in the air box if you service the filter as you should do

I think you could have saved yourself some work by doing then 3x3 AND having a fine filter above the hole