[NCSTEVE83]

Found this in this months Sport Rider magazine:

Introduces Keihin FCR31 Carb Performance Kit for Kawasaki 250 Ninja
Sudco International continues to expand its extensive product line of high performance carburetors kits for street and dirt bikes with this new dual carb Keihin FCR31 Kit for the latest 2008-09 model Kawasaki 250cc Ninja street bikes.

The Keihin Special CR is a pure racing carburetor featuring a larger than stock smoothbore venturi for high air flow and precise fuel meeting. This CR Kit provides for increased horsepower, particularly when combined with other engine modifications. This FCR twin carb kit will work with the stock Ninja throttle cables and can run with modifications to the Stock Airbox, with separate Clamp-On Filters also available from Sudco, or with the tuned Velocity Stacks provided in the Kit. Sudco Part#016-3205 for the Keihin FCR31 250 Ninja is $455.70 retail.

 

[Delta107]

Hmm that's cool!

 

[hi-tech]

ncs u getting this?

 

[NCSTEVE83]

I have put enough money into my bike I think I am done with it. I plan on "moving up" sooner then later, but people that can't move up or don't want to move up may have interest in more power from the 250, so I posted it here for them. I do wonder hom much power you could gain with this mod though....

 

[hi-tech]

this would be good for racer x or ztrck

 

[Racer X]

next thing on my list.

 

[ztrack157]

Got them. Not for around town riding. I have to switch out carbs between the drag strip and riding around town which is fine. Eric down low it will bog down pretty good on you so set your idle to a ridiculous 3500rpm with them. Since your tuned for Mile long runs it wouldn't matter.

 

[ztrack157]

Also not a super horsepower gain. I think the Tis is a Better/Cheaper upgrade since the carbs we have can almost handle anything we throw at it. but if your lacking fuel then yes it would be a great upgrade.

 

[Racer X]

I did not expect much more top end but I thought they made for better throttle response .

 

[ztrack157]

They do as long as you are already rolling. The trouble spot is from idle until about 3250RPM this is why setting the idle at 3500 eliminates the bogging down. I email Sudco after bram had asked me to figure it out for him before I got mine. The President of the company emailed me back. His word verbatim were you can not snap on the throttle at low rpm's but you must ease on the throttle. Replacing the pilot jets did nothing to solve the issue other than wasting more gas. With these when you roll on the throttle all the way the carbs open all the way and at low rpm you get the bogging.

 

[Racer X]

I suspect that is becsuse the throttle opens ahead of the engine load . That is why we have a vacuume operated slide. How do you think they will work in a hevely modified engine ?

 

[ztrack157]

I think you will be fine with it. Your engine is being built mine is MIA until the end of the year so I have no data for you. There is really only one way to find out.

 

[Racer X]

I am going to Bonneville in a couple weeks . Have to save my money for that.