Well I had a beotch of a time setting up my FCR39 from an 04 YFZ. I am posting this to possibly help out a Z brother that may contemplate a FCR install. Let me tell you the pain in the arse is worth it!!

Maybe this can be made a sticky.. First do a search and learn how the thing works and what to expect. Search Thumpertalk.com and this site. Then maybe use this as a guide.

First of all. Take it apart and make sure it is clean. If you look in the mouth of the carb it has a hole in the bottom center of the carb that is the Main-Air-Jet hole. It is not adjustable. It is drilled at 200(info from Sudco). The other carbs(not yamaha I am unsure of honda) have a jet there. When the carb is apart and the main and holder is out you can put a piece of wire or thick fishing line through there and it will end up coming through the main holder brass straw belongs. Mine was pretty much clogged. Clean the pilot passage with a smaller wire. By the way- the Yamaha pilot jets are a type 21.

Make sure the AP diaphragm is installed correctly. Not upside down lke mine was!!!! The larger part of the rivet goes downward. I had a TERRIBLE bog and this was the main culprit .

Adjsuting the AP linkage. The best source for this was Thumpertalk's Honda 450 discussion. link-- http://www.thumpertalk.com/forum/showthrea...4181&page=1 It is a big thread but you should get the idea by the first 20 pages. I read until they talked about the 3 types of mods they were using.

I adjusted the linkage by holding the throttle wide open and adjsuting the screw til it "just touched" the AP black lever after that I did the O-ring mod to the linkage. I made sure nothing would bind.

UPDATE- I DON'T RECOMMEND USING AN O-RING. READ ON FIND OUT WHY

I am not dialed in 100% but I am real close. Check my signature for my jetting.

Also thanks to Normal, RRGUY, NJC, and Jasontallica and I am sure there are others I am forgetting .

Mike

Man...there ain't none of those guys you mentioned that knows what they're doing!!!! LOL j/k You had some damn fine people helping you out....that includes you too Normalz!!!!

just got a 05YFZ carb and am tryin to install on my KFX400 its diff from the FCR thats on my CRF450 thats for sure.well anyways the bottom throtte cable and bracket is hitting the cross memeber and not letting me put carb on all the way. How did you get yours to fit ?
Casey

Bottom Throttle cable? There was only 1 on mine and it barely missed the cross member.. There was not cutout in the carb body for a 2nd cable.

I am no expert but I have never seen a carb from an ATV with more than 1 cable. That is usually from a twist(bike) throttle.

If your slide returns by itself you probably don't need the return cable and can take it off.

If you'd like some pics send me a PM with your e-mail address.

Mike

I disagree... Normalz is a moron... he probably just got a lucky guess. j/k we all know that Normalz knows more than most of us about the z, and that most definately includes me.

My fcr39 is on the way and am needing some jetting tips to start with. Mods are in my sig and since I don't have cams and drz kit will this effect my jetting? Also did you use the drz and 400 ex boots. Just reading up on the fcr until it arrives. I see most people use the drz boot, but don't see everyone using the 400ex also. Does the 400ex boot need modifying to work. I looked at the fcr tips from normal ( http://www.ttbomb.com/z400/fcr/ ) and didn't see anything about the 400ex boot. Thanks

What exactly does the Boyesen Quick Shot do and if you adjust and mod the ap is it still necesary. thanks

Very rarely am I included in the "damn fine people" club - thanks for ruining it for me, PeeWee, ya bastage.


Black Z400, I don't know you, but you're damn lucky you decided to toss in some smilies with that comment, because you just about earned a serious ass-whoopin'.

Ok well I was told it was a YFZ carb and now after you said that I went on internet and looked for YFZ carb and I clearley see that it wasnt. Dam ebay people! Looks like one that comes off a KTM dirtbike or somethin. yes it came with twist throttle as well. yes it does return by itself. this carb unlike the one on my CRF 450 has like mechanical arms on side of carb that move when you do the throttle and link down to accelertor pump etc.looks exactly like this one
carb like mine on ebay

what I need to know is what do i do to make this work?do I cut crossmber notch for throttle cable to fall into and not hit.do I cut that part of throttle bracket off carb and loose the cable since it returns on its own?I really want to do the thumb throttle anyways once i figure out how I do that wit this carb , where do I get the correct cable? do I sell carb and get dif one?Let me know .
Casey
I appreciate the help .

Casey,

I don't feel right telling you what to do because I don't want the throttle to get stuck open under my directions. But this is what I would do:
I would make sure the carb slide will close and close fast on its own. The stock thumb trhottle has a return spring in it so it makes it a little easier on the slide closing. Mine(YFZ) has enough spring to close the slide and pull the thumber back and back fast. Mine is supposed to have the "softer" return spring too.

If that one closed like the one I am using I would cut the bracket and lose the return cable.

Right now I am using the YFZ thumber and cable. I may want to get the correct cable so I can use my stock thumber. You an get them from the place in this link http://www.ttbomb.com/z400/fcr/

Unlike the YFZ carb, the intake bell on that carb is removable. Not a bad thing. There is no way for me to know if it will fit. I don't have an EX boot.

I would also do the "wire mod" that they talk about in Thumpertalk.com use the link I posted in the first post. Make sure it doesn't bind and set the screw with the throttle WIDE OPEN. Check for binding or possible binding again.

Silver,

I didn't use the DRZ boot. I do have one on order cause I dont' trust the stock boot. Carb is not in it enought IMO.

I don't think the QS is necessary. I heard it does improve the way the AP ressy fills. It is supposed to ensure there is no air bubbles in the ressy too. Air compresses and fuel doesn't so it is supposed to give a better squirt. It is also 80 bucks so I would try it without first.

To get the EX boot go to a honda parts site like www.ronayers.com and order a new one. I am using stock boot. Jetting should be similar the EX boot flows a bit better.

Mike

Thanks mmikulak!
I removed return cable and it returns fine. Only thing I have slop in the twist now like 1 inch worth before it actuates carb open.I tried adjusting cable as far as it would go.still there. Quad runs good just need to fine tune it. Will thumb throttle cable for any FCR work on my stock z thumb throttle? I bought one on here from Avalancheharpo
but have yet to hear from him on sending it out yet. will thumb throttle cable just hook up to top cable guide mount on carb like I have now with the twist throttle cable, so I can cut that part of bracket so it wont hit crossmember?

Im runnin 170 main OBDV needel clip in middle 4th clip,45 pilot 65 leakjet 2 1/2 turns on air let me know what ya think

Casey

Thanks mmikulak for the info. I will order both boots, ncvq needle, fuel screw, and jets. Anyone deal with a good and quick place to order jets. My local shops might have some main jets but i don't think they will have many pilots or leak jets. Anyone have a suggestion on jets to start with like 155-160-165-170 and 48-50 pilots and 50 leak and any others or is this to much. I see some have plugged there leak jets wouldn't this give you way to much fuel on a z and also wouldn't this make the ap shoot gas no matter how the throttle is pressed?? thanks everyone.

No, the YFZ cable will not work unless you drill and tap the Z thumber. I can't say for sure if it will hook up the same way. Get that motionpro cable for the stock thumber.

I think that if it is runnig good than you must be pretty close.

Did you get more power???
Mike



I got my jets from the Honda dealer. The main jets were large hex and the pilots are Kehein type 21. Mains as you suggested and piots 45-48-50

Blocked AP will do just as you decscribed.

which way on leak jet makes for shorter squirt going up or down in numbers ?I have a little bog if i stab it real hard. leakjet does what? I dont want to have to buy one of those boysen AP covers if not needed is what I am trying to do.
Casey

Down or lower makes longer squirt. Larger make shorter quirt. Did you adjust the AP like I suggested?

Hold the throttle wide open (til the slide disappears) then screw in the AP screw til it hits. Then wire or O-ring that linkage together.

I dont have the same linkage as you. I have the long mechanical arms like picture i showed above with the carb on ebay.I can still wire that thing up somehow?
Casey

Casey

Look at the one NormalZ posted in this thread. The second picture. Isn't that like yours? Look closely it is wired together.

http://www.z400central.com/invision/index....showtopic=64333

Mike

Yes mine like that..OK ill try that today then thanks.
Casey

Ok I wired it and seemed to help but I still have bog and i think its because my pump timing . It does not hit slide but it goes for quite a while when you whick throttle. I think I need to make it squirt less gas. I have the old style FCR it seems like( same as 2nd pic in the link you gave me) so Is there a leak jet for me to change in that carb or do I need to do the taffy Mod? otherwise the quad runs great i just want it perfect. And want to be able to just whick throttle and it goes without any bog.

Thanks for your help.
Casey

It is not a big deal if it bogs in neutral or with clutch in.

Did you time it by that TT post?
Throttle wide open.
Make screw touch.
Wire together.

timing-
I don't see how it is posible to hit the slide with the squirt. At least with my carb. If you think about it the AP doesn't squirt til pushed and the slide is already moving by then. I can be wrong because i have heard of it happening.

leak jet duration
I am pretty sure theres one in there. take off the bowl, unscrew it and check out what size is in there. it is stmped on side. or someone may have blocked it off. it should be noticable.

How long is duration of the squirt?

I guess I dont know what ya mean make screw touch?What screw? I dont have a screw on mine? All I did was wire thet black plastic arm thing from acc pump arm to the bracket with the spring on it. Not while it was wide open or anything, as I cant hold throttle wide open and hold carb and wire it together at same time. squirt duration at least couple seconds long. Did i do it wrong. Can I call you on phone so talk to you in person ? if so pm me your number.
Casey

sorry man I didn't pay close attention to the pictrue I told you to look closely at.

That is beyond my level. You are welcome to call me but I have NO experience with that one.

Mike which way does that AP diphram go? raised stud tords linkage armso that it pushes on it or raised stud goes tords cover or spring?
Casey

In mine, the large part goes down. That is the part of the rivet that stops the motion.

I threw my boyessen instructions away they had a nice diagram...

Mine had the small portion of the raised rivet down in the cover of the AP not touching the rod with the spring on it. had the other side with retainer lookin ring touchin the AP llink arm. I think mine is upside down but cant find a picture of how it should be. looked at microfishce looks like mine upside down but hard to tell with the microfische.Casey


ok I found pic mine is in correct
http://www.thumperfaq.com/ap.htm
casey

ok I found pic mine is in correct

was IN Correctly or was IN incorrectly? You described it as upside down.

quick question man, i read the post on tt, and do I need to shave the diaphram? Or can i do like u said and hold it wide open, make the screw touch, and wire it.

Mine was in properly. so that is not the reason. Im gonna go down on the pilot from 45 to 40 (guy on thumper talk (Shawn MC) suggested my pilot to big) and see what that does. If in nuetral idling still If I whick it to wide open it will die sometimes or just deadspot! under normal riding I dont notice as much as only roll on the gas. I wired Arm, Did Taffy Mod so only have very little squirt .5 seconds about and I still have bog,so maybe it is the pilot. I sure hope so. Ive taken this carb off 100 times in the past few days.
Casey

Shouldn't have to shave it. I believe they shaved it to get the arm to move more(more travel.. Just try touch then wire or o-ring. That should have enough travel to not bind.



Can you "borrow" your boyessen cover from the CRF??

Yeh I could. Kind of a pain to take off the bike but yes thats a good idea! Try it and if it works we know what to do. Good Idea there Mike. Plus that might also have diff leak jet or Pilot in it I could try. Instead of buying till I figure out.
Thanks,
Mike ill try today after work.
Casey

Mike I finally got it. found out I do not even have a leak jet! so i cant do the wire the AP arm can only do Taffy Mod which I did then it ran heck of lean so i bumped main all the way to 175 then needle to 5th clip and it rips with no bog. I need to go fatter on Pilot still a little poppin under de acceleration and hard to start unless I pump it a few times. im very happy now.
Thanks for all your help.
Casey

Glad you got it Casey !!!!

UPDATE___

Hi guys,

I wouldn't do the O-ring mod. I was wondering why my bog came back. Darn O-ring broke.
DRZE boot came in. It doesn't fit . The carb will not get that close to the head. It needs a turn. Maybe it is the FYZ carb.


I fabricated a clip to hold the AP lever and the linkage together. I wanted to wire but didn't have any and figured the wire would loosen with time so I made one out of a piece of stainless.

Would someone mind posting the pics? I don't feel like figuring it out.

OK. It has been a while the pics are at www.members.cox.net/mmikulak the pics are big!!

send me the pics and i will post them up for u man. Michwolv60@sbcglobal.net. If I like what I see in the pics, I might even buy one off u and clip the wire i have around mine.

bump

looks good man. If my wire loosens up or breaks i will have to go with your idea.

Anyone know why the drz boot isn't working, I just ordered one? I haven't been able to find alot about using the 400ex boot and which year you need. Is the 400ex boot longer to cure your problem and does it hook right up the the air box with no mods?

The DRZ boot did not work for me either, I used the stock boot by heating it up real good with a blow dryer and stretching it over the carb, it is slightly longer than the DRZ boot also. The clamp is a little too big by a hair so to temporarily fix this I just put a few wraps of electrical tape around the o.d. of the boot until I get a retro fitted clamp of some sort. but I ditched the DRZ boot idea and have not tried a 400 boot.

We are talking carb to head. The little boot.

The DRZ-E boot is too short. Plus it is straight. My Carb hits the X-member and the top of the mouth of the carb will not get close enough. See pic on my site listed above the carb was jsut sitting but you get the idea.

The stock one has an angle in it and is a little longer.

DRZE Boot for sale. I paid 15 bucks. 5 bucks shipped.

Me too.....$4.99 shipped though

gonna bump this. Maybe it could be a sticky?

HINT HINT

Done brother! Good topic by the way!

Here's the link to the 2 mod options put together in PDF format: http://www.squadpage.com/pandora/Professor...%20AP%20Mod.pdf


This is the same thing put into a retail kit:
http://jdjetting.server304.com/xcart/produ...at=5&page=1

not to contradict what mmikulak said about the drz boot not working but I used the drz boot with an edelbrock head stay and I used a 3" steel pipe and 3" turbocharger hose cut to length on the airbox and it fits like a glove, doesn't move a bit.

You aren't contradicting me. That was the problem-the stock head stay.

You got around it by using the Eddy Head stay-which I didn't know existed til you posted it a while back.

Thanks for letting us know.

MUX

I would just like to remind anyone who is installing these carbs to make sure (especially if they are used off of ebay) to tear them down completely and make sure that everything is to spec, i was having a hell of a hard time to get mine to work at WOT and after getting completely frustrated i tore it down and found out that the Float hieght was set way way too low.

Also i put on a raptor 660 Petcock in replacement to my stocker and it seems to flow alot better than the stocker as well.

What height did you set yours to? I bent my tab on the float because fuel was pouring out of the overflow tube but now I am not sure if I am getting enough ot too much fuel to the carb?

I don't have the manual with me(I am in Boston). I think it is 14mm from carb body (where the bowl sits). Also, try to get the carb on as straight as you can.

MUX

How much does one of these carbs cost and do you guys buy them new or used?

my carb was $169.48 ,got it off ebay, then there was the throttle cable and the thumber so it was about $200. deal for me, new carbs are a arm and a leg.
there are some other things to like a C2HB and a different intake boot (which was free) a better AP cover and the right jets .