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General Category => Modifications => Topic started by: fjryder on June 04, 2010, 04:12:11 AM

Title: Keihin FCR 41's?
Post by: fjryder on June 04, 2010, 04:12:11 AM
Has anyone run Keihin FCR 41's on an FJ? Mine is an FJ1100 that is getting a 1250 kit and probably cams/valve work. Thanks.
Title: Re: Keihin FCR 41's?
Post by: Pat Conlon on June 04, 2010, 11:37:49 AM
Over the last couple of years, I have been told that the sidedraft Keihin FCR's have been very hard to come by. Very rare.
IIRC Frank M and Steve C both have monster 1349cc motors in their FJ's, and they have only needed the 39 FCR's
Therefore, for only a 1250cc motor the 41's sound a bit big....however if 41's are all you can get......
The FCR's have been reported to be superior over the Mikuni FS38's but, then again, the FCR's have no choke function.

Frank, Steve?
Title: Re: Keihin FCR 41's?
Post by: racerman_27410 on June 04, 2010, 04:39:55 PM
waaaaaaaay too big for the FJ......    im fairly sure the spacing would be all wrong for the FJ unless they were originally bought specifically for a drag racing FJ

my 1349 pulls to redline (hard) with the FCR39's      i can get about 40mpg if i take it real easy or i can hammer out some serious KOoKaLoo and drop that right on down to about errrrrr 27 or so  :diablo:

stock are 36 and are very capable of working well in concert with a 1250 motor.... if you go too big on the carb you lose the intake velocity.... according to my sources the FJ has a inefficient combustion chamber so you need to make sure you get good fill by keeping the intake velocity high with a smaller diameter carb.  the mikuni 38's might be a good choice for more on the big end BTBH i had some RS38's and i didnt care for them and their forearm pumping throttle spring even if they did have a choke.

ze kookaloo is goot no?   :good2: