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im trying to fit a fcr39 carb of a 04 yzf to a 01 drzs , im having issues fitting it ,throttle wheel hits frame etc found help for that problem. just when i try fit airboot and subframe to carb i have approx 10mm gap and cant figure out problem i bought a e model airboot

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sorry might not have been clear enough im not good with computers basically when everything is installed i have a gap of 10mm between back of carb and air boot. drz s with 04 yzf fcr carb drz e air boot am i missing a part?thanks

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I had the same thing. I tighted the adaptor from the head to the carb then gently pried the carb back onto the air boot with 2 long screwdrivers. while using my once hand a leg to pry i used my other to tighten the clamp.... good luck

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it wont work.it has a non removeable intake bell.

you cannot fit the proper adpater to make it fit the air boot.

the cable tower is also as notes.

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i put the same carb on my 06 s model. the gap will have to be taken up with some customizing. Its do able. But it is very difficult to close the gap properly. As far as the cable housing goes. the carb will have to tilt to the left slightly. Not the best setup. Best option is to off that carb and find different one from a honda or suzuki.

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thanks for help i thaught all fcr carbs were similar enough to install my mistake , so rmz or crf any year do ? i dont want this problem again ,also would a new fcr mx carb fit straight in there with e model air boot or do i also need adapter

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whats the story with the removable air bell i asumed the carb body was one piece

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I actually just completed an install with a 1 piece body FCR carb on my 05 400SM. It took some work, but I did it in a Saturday morning.

The carb body around the throttle wheel hit the frame, so with a cut-off wheel on my dremel, I removed the cast aluminum around the wheel. The clearance of the throttle wheel to frame was a little too close for comfort, so I "massaged" the frame slightly - Enough of a dent to provide clearance.

With a KTM intake boot between the cyl head and carb throat, I was nearly line-line with the intake horn and air box boot. I bought a piece of 1.5" ID rubber black iron pipe coupling, and chucked it in the lathe with an expanding mandrel. I turned the OD down to the size to fit in the air boot, then sized a piece of aluminum tubing (thin wall) to fit in the rubber coupler, that way the rubber coupler/air boot had support when clamped.

The other end of the rubber coupler fit snuggly around the intake horn with a little soap to get it to slide.

I wasn't sure about the rubber couplers resistance to fuel, so I smeared a light coat of "Seal-All" on the ID. This stuff is used to fix oil pans, etc, and is supposed to be fuel resistant.

I've got to play with my jetting some more, so the carb is coming out this weekend. I've got some silicone hose (used in turbo intercooler plumbing) that I'm going to replace the rubber coupler with. I'm also going to machine an aluminum insert to go between the carb and air box boot.

The E intake manifold should give me a few more mm's of clearance between the two, so my aluminum insert should fit nice. I'll try to take pics as I go along, and post my results.

Making a CRF/RMZ style FCR is not an easy bolt-on install like the kits sold here, but hey-I got my FCR for free!

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fitted yzf 450 fcr to my sm last week,went pretty smoothly only issues were going to single throttle cable,s/sm return cable doesnt fit throttle tower.

used yzf front carb rubber,no vacumn tap on most uk drzs.

airbox boot is a bit of an issue,loosened airbox,then fitted boot to rear off carb.seems ok for road use,but for muddy,dusty,wet use will need to make sleeve of somesort to ensure doesnt leak or slip off.

blanked off air valve junk and runs pretty good.whole episode didnt take long.

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it still doesnt adress the issue of the flat transition of the intake bell.

Eddie, I'm not following your response.

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the back of the carb is flat,not tapered.all of that style oem fcr are intended to be used with the stock air boot from which ever bike it came from.it continues the velocity stack.

the jetting will never be 100% correct with what you have going on there.

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Ah, I got you now.

The air boot on whatever this carb came from is "tuned" for this carb, since there is no nozzle leading to the venturi, such as the air horn on the fcr that is used for the DRZ conversions.

I'm gonna have to pull out the old fluid dynamics book...

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