Carb for stroker engine

[thebig450es]

i was thinking of using a 450r carb, but what else has people used with with better outcomes on a stroker engine. Thanks

[Thumpin440ex]

450 is prob the best one out there rite now. If you want to tweak a little more to get it to fit, a FCR 450 carb is great also..


John

[Wheelie]

The 450R carb works great in my application--no complaints.

[thebig450es]

I saw some FCR 39's for sale , i want a easy carb to tune if thats possible lol

[Colby@C&DRacing]

I would recommend the 39mm fcr carb this carb is a bit pricey but works well for the application.

[thebig450es]

could you pm me a price?

[JOHNDOE83]

For a stroker, the 42mm 450r carb would be best.

[thebig450es]

What would the best way to fit a fcr carb on a 400 from a later model 450r?

[IMSROLL450R]

I just put the 39mm FCR on mine and it was EASY to get it to fit and EASIER to get jetted right. I used a rubber fernco between the head and carb that added 2 1/4" long so that it moved the carb back enough to easily clear the tank. The stock intake tube fit perfect on the back of the carb. it was literally a 30 minute install. I started on my bigger head 440 with a 165 main and 45 pilot and ended up with a 170/48 with the screw 2 turns out. I couldnt be happier. I have heard SO many people on this site say that the FCR is hard to tune. It was so easy that I feel like they must have been smoking crack while tuning it because with ANY jetting knowledge its just a downright simple carb to work on. Not only that I would challenge any 450r carb to have as good throttle response as the FCR flat slide. Just wont happen.

I vote the 39mm FCR. Get a 450 cable, install it, get it jetted, and you WILL NOT be disappointed.

[CJM]

What exactly did the 39mm FCR you get come off of IMS (year, model, etc)? and what is a "rubber fernco"?

[IMSROLL450R]

Originally posted by CJM
What exactly did the 39mm FCR you get come off of IMS (year, model, etc)? and what is a "rubber fernco"?

It came off of an 06 YFZ and a fernco is a rubber piece of tube with a clamp on each end. Usually used in plumbing to connect 2 pieces of pipe. I used one that was slightly larger on one end because the intake portion that bolts to the head is too small to go over the output side of the FCR. Everyone talks about the carb hitting the bottom of the tank so I thought instead of making the intake up on the airbox side, why not move the carb back and avoid the tank issue altogether:ermm: I will get pics when I pull the plastic and tank back off to check the valve shim after break in. Like I said, it was SUPER easy, and after riding this 416 with the 450r carb, there just is no comparison.....

[CJM]

Interesting. I know the plumbing part you speak of, its like a big rubber adapter right? So you just stuck it to the 400ex intake boot or something?

Very cool man, cant wait for pics.

[thebig450es]

IMS, some pics would be great, this will be great ...something better than the 450r carb swap. with the 452 stroker and race porting im looking for a carb to be up to par.

[400exshop]

The best carb to run and tune is the 39fcr get it tapper bord to the 42.5 ..........and get the head ported by some one that know what there doing.....get a set of +1 valves put in and she will fly and have a *** of power all the way through..... trust me you need the head ,valves,carb, cam and strock to work as one not a bunch of stuff gut put on there..... ps make sure you have a good flowing pipe.

[NacsMXer]

Originally posted by IMSROLL450R
I just put the 39mm FCR on mine and it was EASY to get it to fit and EASIER to get jetted right. I used a rubber fernco between the head and carb that added 2 1/4" long so that it moved the carb back enough to easily clear the tank. The stock intake tube fit perfect on the back of the carb. it was literally a 30 minute install. I started on my bigger head 440 with a 165 main and 45 pilot and ended up with a 170/48 with the screw 2 turns out. I couldnt be happier. I have heard SO many people on this site say that the FCR is hard to tune. It was so easy that I feel like they must have been smoking crack while tuning it because with ANY jetting knowledge its just a downright simple carb to work on. Not only that I would challenge any 450r carb to have as good throttle response as the FCR flat slide. Just wont happen.

I vote the 39mm FCR. Get a 450 cable, install it, get it jetted, and you WILL NOT be disappointed.

I use the FCR39 on my GT Thunder stroker as well. I got it from Sparks Racing so it was already set up to bolt right on to the 400EX. That's funny, we both live in IL so elevation is similar, both run the same carb and have very similar jetting specs. I definitely agree that the FCR is a superior carb design.

Here's my current specs:

Pilot: 50
Fuel screw: 1 3/4 out (65 degree weather)
Needle: 5th from the top
Main: 170
Main air jet: 200
Air screw: 2 1/4 out

http://img593.imageshack.us/img593/4554/dsc0157gu.jpg (http://img593.imageshack.us/i/dsc0157gu.jpg/)
http://img130.imageshack.us/img130/2181/dsc0158rh.jpg (http://img130.imageshack.us/i/dsc0158rh.jpg/)

[CJM]

Sadly I have a nice 450R carb waiting to go in, oh well its gonna go on sooner or later. I can always find an FCR39 down the road off a YFZ.

[thebig450es]

Thanks Nacs, oh yeah your in box is full, i got that info from laz

[NacsMXer]

Originally posted by thebig450es
Thanks Nacs, oh yeah your in box is full, i got that info from laz

No problem. Thanks for letting me know about my PM box, I had no idea sorry about that.

Should be good to go now if you could send it again please, thanks man.

[IMSROLL450R]

Hey big450 I forgot if you want to see pics of my carb mounted look at my build thread of the bike before plastics, there's some on there. Its titled 01 Red and Black build.

[SHIFTx450]

What size was the fernco, 2 to 2 1/2 ?

[thebig450es]

I got my engine installed now and im working on installing my carb. I was thinking of matching Nacs jetting to start off with but im about 1150-1200ft elv. so the air is thinner, how much of a difference should that make? Better to start richer