YFZ450 FCR to DRZ400

[LiveFastDieAwesome]

I found a really good deal on a 04 YFZ450 FCR carb, and i just wanted to make sure it would fit on my 02 400s. i know it'll take a few slight mods to make it work, but i just wanted to make sure that carb would be compatible with my bike before i buy it. im currently doing a 440 kit, with HotCams and i figured i'd just go ahead and do the carb while i have everything torn apart. thanks!

[Craigo]

you are thinking of purchasing a 8 year old carb with an unknown history....?...Good luck with that...It's gunna be a crap shoot...I would not touch it..

[Smias]

Αs Craigo said it's an old with an unknown history carb...

Also from '03 & after the YZ450 carb doesn't have a removable air bell intake to the air box so it will fit properly .

They need a machined adapter to fit properly .

I would pass and save money to get a new Fcr .

[speedtoad]

I know more about this then anyone here because I've got one on my DRZ. It works great! I too got a great deal on mine. Here's the problem, and it's a big one, the low speed adjustment doesn't on the carb won't fit it the frame. You have to cut it off and aluminum weld or braze a bracket and new adjustment screw on like in the picture. The FCR MX is a great carb. I bought new jets for it. Would I do it again, not unless I got a better deal on the carb. Although if you have some carb knowledge I would still buy a used one on ebay if it looked to be in good shape or newer.

http://www.thumperta...__fromsearch__1

Edited February 25, 2012 by toadl

[LiveFastDieAwesome]

Awesome thanks alot for that info! my buddy said we will sell me his 08 39MM FCR from his yz450f for pretty cheap. im thinking about doing it.. it comes with the throttle tube and cables/hoses.. if someone can tell me to go for it ill buy it today

[speedtoad]

_{Hey man, thanks for that info on my thread! i have a few questions on the modifications you were talking about on the carb tho. could you explain a little more? thanks again i really appreciate it.. Also, was it a pretty direct fit swapping the FCR in?}

_{Use the boot that and clamps from the yfz that go between the carb and the cylinder head.}

_{Use the DRZ400S boot from the airbox. the clamp for this boot is to big or small, I can't remember, but you can use an extra clamp from the other side of the DRZ carb.}

_{I used the DRZ pull cable, but if you have the YFZ cables, give them a try. I'd like to know how the length is, because I might want to buy a set of the push/pull cables.}

_{I had to grind some of the Throttle cable cover off to make the carb fit in the frame.}

_{A lot of people don't use the cover but because of the way this carb is designed it's easier to use it.}

_{It will be tough to get the intake boot on the carb, which is common. Just unbolt the air box, put everything together and then bolt the airbox back on.}

_{For jetting I used www.jetsrus.com . EMN needle. I can't remember the rest but it was pretty common FCR jetting. I had to go up one pilot jet size. The carb I used had stock jetting. You could install the carb and see how it runs, but I eventually would change the needle.}

[LiveFastDieAwesome]

Sweet thanks again man. so whethere i go with the 08 or 04 carb i should be good to go? sorry for all the questions, i just want to make sure either one of those will be fine to use, functionality wise.

[speedtoad]

questions are okay. That's why I joined the Forum, I like to talk about my bike and get ideas and knowledge. Good luck and wish me a happy birthday. I have to join the party now. Funny thing about birthdays is you have to do what others want you to do. Right now I want to Finish putting new seals in my forks. That's life.

[bonher]

whats that that u used to plug the hot start? i just purchased the pull out knob because i too am using a yz450f fcr.... off a bike though... couldnt find a plug kit anywhere. and i see u didnt use the motor vacumm do u just run the bike on prime?

[speedtoad]

whats that that u used to plug the hot start? i just purchased the pull out knob because i too am using a yz450f fcr.... off a bike though... couldnt find a plug kit anywhere. and i see u didnt use the motor vacumm do u just run the bike on prime?

I'm a little confused. The prime is different then the hotstart. The plug in the hotstart is stock on the YFZ. It's just a plastic plug. I don't know if a metric screw would have the right threads but you could try that with a gasket. Or look up the yamaha number. Sorry I'm not much help. Like I said, the carb came that way.

Was the Yamaha YZF carb easy to install?

Edited March 13, 2012 by toadl

[bonher]

its not in yet. im waiting for the emn needle and hot start .... should be 2morrow ..... the carb came with threads in the top..... the yzf comes stock with hot start connected to a cable that runs to the handlebars so i got the pull choke style just to plug it up..... did ur carb have a fixed main air jet (just a hole on the bellof the carb with no threads)?

[bonher]

oh and about the prime..... u got 2 hoses comin out the tank right? whered u put the small 1?

[npm]

If you are talking about the vacuum line you have to find a source for vacuum as you don't have one on the FCR like you did on the Mikuni. Put a nipple on the head for this purpose. If you do a little searching you will find a picture on here somewhere. You could change over to a manual petcock or run on prime but if you do that you will lose the reserve feature of the tank.

Edit: I found this thread showing the vacuum nipple, it's in the picture in the first post.

https://www.thumpertalk.com/topic/893663-what-goes-here/page__p__9300734__hl__vacuum%20nipple__fromsearch__1#entry9300734

Edited March 13, 2012 by npm

[speedtoad]

its not in yet. im waiting for the emn needle and hot start .... should be 2morrow ..... the carb came with threads in the top..... the yzf comes stock with hot start connected to a cable that runs to the handlebars so i got the pull choke style just to plug it up..... did ur carb have a fixed main air jet (just a hole on the bellof the carb with no threads)?

Yes it did. I still used the same pilot jet everyone else uses. Can't remember the size off hand, maybe 24.

[bonher]

24 pilot air jet? I heard no pilot air jet or 100 pilot air jet..... I'm not sure what to do beacause it has the fixed main air jet..... hmmm

[deriksowlcowski]

i know its been a minute since anyone posted in this thread but i was wondering if you got the carb working right in the bike and what modifications it took to make work?

[-=fusion=-]

I've done an extensive thread on fitting a yfz thread here. 

Still need to update it with my jetting as I've got it pretty good now.