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What intake manifolds will fit on XR650L/NX650 engines?

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In need an intake manifold for my NX650 that runs straight back off the engine and is as short as possible. The stock NX manifold runs straight back but it's too long. The XR650L and XR600 boots are shorter but they don't run straight back, they turn to the side.

I'm trying to fit an FCR MX onto my NX650. The frame, with the square tubing, is different than the XRs and the boots suggested in other posts about fitting this carb don't work as they put the carb right into the frame. 

Will an XR250 boot fit on the larger bore bikes such as XR650/NX?

What other bikes have boots that will fit these motors?

 

Here's a couple of pages talking about fitting an FCR onto XRs. There's one guy who made a steel manifold. I could do that but it's my last resort. Not the route I wanted to take for this bike. 

http://www.thumpertalk.com/topic/1009853-complete-guide-to-installing-fcr-mx-on-a-xr600/

http://www.thumpertalk.com/topic/995444-fcr-40mx-carb-awesome-upgrade/page-14?hl=nx650#entry11015265

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Try:

 

GB500

FMX650

RS600 (may be custom, race only engine)

Edited by Onederer

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that's my steel manifold , was a real pain to make as there is no room at all to play with , the carb would only fit in one position,

as you know the carb cant go any further back or lower because of the rear shock mount and the frame gets real tight where the square tubes meet the oil tank ,

I've had to mount my carb twisted and to the left just so it would fit between the frame tubes,

was a lot of effort to make it fit but worth it.

not sure you'll find anything that just bolts up , but best of luck and let us know if you find anything

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that's my steel manifold , was a real pain to make as there is no room at all to play with , the carb would only fit in one position,

as you know the carb cant go any further back or lower because of the rear shock mount and the frame gets real tight where the square tubes meet the oil tank ,

I've had to mount my carb twisted and to the left just so it would fit between the frame tubes,

was a lot of effort to make it fit but worth it.

not sure you'll find anything that just bolts up , but best of luck and let us know if you find anything

Nice work on the bike. I will let you know what I find. 

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If you take a close look at this pic it almost looks like the frame is notched.

https://plus.google.com/photos/+bikeexif/albums/5962885542338190945/5962885551700198610?pid=5962885551700198610&oid=101554244823678290874

 

Here are some large images:

https://plus.google.com/photos/+bikeexif/albums/5962885542338190945/5962885551700198610?pid=5962885551700198610&oid=101554244823678290874

The pod comes straight out of the carb over the shock which makes me think it's a short, straight manifold off of some other bike. 

Here you can see it is clearly an oem rubber manifold:

https://lh5.googleusercontent.com/-OqtGzDeqRK8/UsBs6DUgCkI/AAAAAAAAJd8/_oQZevnxiAw/w2000-h1335/2013-12-06-kiddo-2-89.jpg

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that does look like the stock boot , and the cover is still fitted over the pulley wheel,

no way mine would fit like that ,

notching out the frame would give you more room but not sure its a great idea ,

would like to know how he got it in there  hmmm  :thinking:

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Hard to tell but based on my read of the bad angle of this drawing it might be the manifold off of a fmx650. Thanks Onederer. This bike must not be available in the US because I can't find parts in the states or on ebay. 

http://www.bike-parts-honda.com/pieces-honda-detail-2184-17MFC5S1-FMX6505-2005-E__0200-FMX+650+FUNMOTO+34HP.html

Update

Don't think it's the one. 

http://www.cmsnl.com/honda-fmx650-2006-englandmkh_model8040/insulator-carb_16211mak003/#.U_FRyFa_1Y4

Looks like it makes a hard left out of the engine. 

Update

http://www.cmsnl.com/honda-gb500-tourist-trophy-1989-usa_model1071/insulator-carb_16211mk4621/#.U_FSy1a_1Y4

GB500 looks like it comes straight out. But the part is not available...

Edited by ampsrampstramps

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my bike is a '95 it uses the same boot as a 96/97/98/99/00/01/02 and it didn't work for me ,

having said that those pictures sure do look like my stock boot and that carb seems to fit ,

I can see i'm going to have to dig out my stock boot (which has a big split in it anyway so no good) and try again ,

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my bike is a '95 it uses the same boot as a 96/97/98/99/00/01/02 and it didn't work for me ,

having said that those pictures sure do look like my stock boot and that carb seems to fit ,

I can see i'm going to have to dig out my stock boot (which has a big split in it anyway so no good) and try again ,

I'll let you know what happens. Waiting on one from France. 

Where'd you get your bike? Must be a European model. 

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Got the boot from France off a 96-99 Dominator. The FCR does not fit in the frame with this boot. It's close but there is no way you can get it to fit as is. 

So, looking at my options 1. Cut the frame or 2. cut the carb. I cut the carb.

The part of the carb that hits the frame is right where the push cable goes in. I took the push cable off of the carb so it is a pull throttle only and chopped the push cable holder off of the carb.

Fit right in and fired it up. 

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that's worth knowin   :thumbsup: may consider this fitment method myself ,

took another look at those pics you posted and can see only one cable coming from the throttle so maybe they did it the same way ,

so did you get to test ride it yet ?

 

i'd try and add some extra support for the carb as these boots are prone to splitting , mine did when I had the stock carb and a pod filter , carb would bounce around a bit without the support from the airbox boot , or have you found a way of hooking it up to the airbox

Edited by paint it black

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Yeah. No lighting or plates on the back so I just went up and down the block until the ratchet strap I was using to hold the seat and battery on got caught in the rear hub... 

Seems good though. I had Dave's mod on the stock carb with a power bomb and Q4. It was loud and not a thumping loud, a real annoying clap. 

Dave's mod didn't do much for throttle response until I changed the exhaust. It really kicked once I got the stock header and mufflers off. 

With the FCR the sound is a deeper thump as you would expect to hear. Maybe it was too lean before with the Dave's Mod suggested jetting with the PB and Q4. 

Pics soon.

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any pics yet ?

very seriously considering this fitment method and ditching my homemade boot , 

also be looking at the possibility of hooking the return cable into the pull cable mount and making a new mount for the pull cable ,

screwed into the hole where the screw for the cover goes , probably wont work but would prefer to keep the return cable if possible

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I'll take some pics later today when I have it apart again. Can't really see anything with the tank on. 

What jetting are you using? I followed the DotCom jetting and maybe it's my location, maybe it's my engine, maybe there's a problem with the carb but it seems way to lean to hold an idle with a 40 pilot. 

Working my way up through the pilots today. 

Sorry for delay. Been out of town. 

 

any pics yet ?

very seriously considering this fitment method and ditching my homemade boot , 

also be looking at the possibility of hooking the return cable into the pull cable mount and making a new mount for the pull cable ,

screwed into the hole where the screw for the cover goes , probably wont work but would prefer to keep the return cable if possible

 

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i'm not 100% sure but think I ended up with a 42 pilot ,will confirm next time I have the carb off , also have my needle on the third clip down and a 155 main ,

i'm running a air/fuel sensor on my bike so know that its spot on now ,it was reading slightly lean on the second clip the third was perfect ,

could be down to the huge k+n pod filter and home made exhaust , i'm in the uk at about 200ft above sea level

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Not sure what is up with the pic poster. It rotated the first pic 180 degrees. I post the first pic because the intake manifold is eye shaped rather than the stock oval shape.  

nx_0523.JPG

 

Chopped the top of the carb off

nx_0526.JPG

 

This is the minimum I had to cut the plastic back. I'll fine tune it later. Might weld a slab of aluminum back on to the top of the carb. 

nx_0530.JPG

 

I've got to do some work on the exhaust. Put an XR650l powerbomb header on but it doesn't fit quite right and an fmf powercore muffler.

nx_0547.JPG

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