[crfsonly]

A critical function of the FCR carb is the accelerator pump. The AP is what provides the initial fuel off-idle. A poor or non-functioning AP will result in hard starting and off-idle bogging. Over the years Honda/Keihin made improvements to the AP. Fortunately, Honda released this update kit that can be fitted to any of the FCR carbs with or with these original parts.

http://www.crfsonly.com/catalog/product ... ts_id/3932

Here's a How-To on installing this kit on a FCR carb with the original AP parts.

http://crfsonly.com/howto/keihin-fcr-ca ... rf450r.php



Feel free to post questions or comments about this product or installation here.

Ken

[Hotrodryan]

Hi Ken,

Great site!!! I've been browsing quite a while but just joined last nite.

Ken, what bikes is this fix applicable to. More specifically will my stock 2009 CRF250X benefit from it. Thanks again.

[crfsonly]

Welcome to CRF's Only!

Your '09 had this updated AP set up.

Ken

[BluCallr]

Doing update to my 2004 450r, can I use my boyesen accelerator pump cover & keep existing check valve ?

[crfsonly]

Yes, this is possible. The reason the check valves are in the new covers instead of the bowl is to decrease how long it takes to build up pressure in the pump. A better solution would be to install the Boyesen 3 (with adjustable leak jet circuit).

Ken