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Another Carb Question

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I've been sniffing on replacing the stock carb on my 01 XR400.  I have read posts dating back 5 to 6 years on the subject which include MANY different makes,  models and sizes.  Given the time and effort people have put into researching this topic I'd like to come a consensus on what's the best offerings right NOW (Fall 2013) with respect to .......

 

1.  Improved Starting

2.  More performance

3.  Future Big bore kits

 

 

 

Thanks in advance for everyone's thoughts.
 

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Anyone?

 

Mikuni 36 Kit

BST40

BSR42

TM40

FCR ??

 

Mikuni 36: Works decent for stock bore, expensive

BST40: Works good for stock bore, inexpensive, but needs quite a few mods to install properly.

BSR42: Works good, big enough for big bore, inexpensive, needs a carb spacer and a few minor mods to fit properly.

TM40/HS40: Probably a bit big for a pumper carb

FCR: The ultimate carb but you will need to hack a lot of things apart to fit it.

 

As far as starting, all of the carbs are easy to start.

Edited by mudguy

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The Edison Approach here might have what you need. Lots of posts.

(if someone can do a summary and add it to the FAQ as a post, that would be great.)

ADV Rider is another source for info.

http://advrider.com/forums/forumdisplay.php?f=15

Some wrote that he installed a FCR off a WR250 and it worked great, but never shared the jetting specs. A friend of mine installed a FCR39 and it ran great, but was a nightmare setting up the jetting from what Sudco sold him. The bits you may have to jet correctly are, main jet, needle jet, needle (in various tapers, raise or lower), pilot jet, fuel screw, accelerator pump screws.

Jetting tips (FCR for Yamahas)

http://www.thumperfaq.com/jetting.htm

If you shop for used FCR carbs from 250f bikes, do some research first. The carb size used varies between the MX and enduro bikes and between companies. Honda ran larger carbs than other companies on their CRF on some years.

Length, height, and opening sizes all come into play. If you find a great carb, please share the specs.

Edited by Kev_XR

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Anyone know off hand (so I dont have to pull it off and measure it) what the openings are for the XR400.  Intake and cylinder side.

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