My friend Just got his motor Back from LRD yesterday, We put the motor back in, then we put the FCR 39mm carb on. The problem is the gas tank sits on top of the carb and it won't go down all the way. The carb seems to sit way to high. PLease give me any tips or tricks on how we have to mount it?


Thanks

 

What is this carb going on? My 39mm FCR fit perfectly on my 400ex....

 

Same here, had plenty of tank clearance on my 400EX....

 

This caught my attention because I just bought a 39mm FCR for my 400EX and haven't installed it yet. Maybe he's trying to put it on the 2001 Raptor that's listed at the bottom of his post. Anyways; since we're on the topic, are there any jetting problems that people have encountered with the FCR? I have a 10.6:1 86mm piston, high rev CDI, HRC cam, K&N, e-series silencer and elevation is about 800' to 1000' above sea level. I bought mine from Curtis Sparks and they said that they would send extra jets along with it- but they didn't actually send them.

 

Sorry, it's for my friends 400ex he just got back from LRD. It seems to sit way to high.

 

how do you like you carb i just bought one for my 440 im waiting for my sparks pipe so ill only have to jet it once ive got a whitebrothers now was it very hard to dial it in any hints or tricks would be great thanks

 

When I was running the 39mm FCR on my 426 set up I was using a 162 main jet, needle on third position. I am between 4 and 5 K feet..
I am running a full Big Gun, 450/451 cam, 11:1 piston, and K&N w/modified airbox...very mild match porting... cdi module....

Now I Run a 440 by LRD with 11:1 coated piston, and a very free flowing port job, and I run the same carb with a 172 main and needle on 4th position. I think I will be moving up to a 175 main jet when I go to the dunes... It is running very good now. I think I am right in the ball park for my area...

 

I'd double check everything.... Mine fits perfectly with probably more clearance between the tank and carb than the stocker.

Maybe they sent you the wrong airhorns?

 

I'm running the XR cam, 87mm 10.8:1 JE, mildly ported head, modified airbox, and modified stock exhaust system.

I am currently running a 170 main, 52 pilot, and 3rd notch on the needle. I also modded the accelerator pump to kill a hesitation when the throttle was wicked open.

It seems that you need to be 1 or 2 main jet sizes larger than with the stock carb. This is due to less vacuum pulling fuel thru the main of the larger carb.

Perfect fit and excellent gains throughout the powerband... A definite thumbs up on this carb.

Does anyone else have the metallic rattle when cold? Almost sounds like piston slap, but it's the roller mounted slide in the carb.