tuning a 39mm FCR Carb

[Gen1Pat]

It does do that doesn't it? Been so long I forgot.

 

[duneracerweston]

Update:

changed jetting
52 pilot
175 drilled to somewhere around a 190 (to big)
needle on the 4th notch from the top.

also running a prototype airbox delete on it so i know its inhaling properly.

it pulls like a mofo, it doesnt even feel like the same motor! my warrior with the um box 10.25:1 gytr slip on and a hcs1 didnt run this smooth, crisp or quick. not as fast as walle but this carb is deffinently the way to go for anyone looking for more power even on a slip on exhaust and drop in filter this will help! i am sold out on this carb! ive got the jetting close, the main is a tad fat and the pilot is either lean or i need to fiddle with the A/F screw. i have got about half the bog out with what little time i had to work with tonight. probably wont get to touch it again till this week end but i will keep you up dated!

Pat you got a deal on the carb! i finish up these parts and send em to you along with those two we talked about testing for me.

here is the intake

 

[duneracerweston]

BTW did anyone else notice the rev limiter in the sound test video?

 

[88WarriorBoy]

Yeah I heard it lol a raptor rev limiter must be pretty low lmao

 

[duneracerweston]

Yeah I heard it lol a raptor rev limiter must be pretty low lmao

thats bouncing somewhere around 9k.

i love the sound of a good tak out!:iagree: makes me almost as week as $100 bills!

 

[DeadLastRacing]

It required to run no box like that? To exposed for me and how/where I ride.

Also, why did you drill the 175 to a 190? They dont make mains that big for it or you just didn't have any extras?

Anything you need to remove from the stock carb to make it work?

 

[duneracerweston]

The stock filter was stopped up and i hate cleaning filters and wanted to try a no air box setup on it so I can have a closer tune to mine when I swap the carb over. so it doesn't have to be run open like that, just how i wanted to run it to make it easier for me to tune it to a base line. it functioned fine with the air box on it, just to lazy to clean the stock filter.

I didn't have anything bigger on hand, will get the jets I need hopefully tonight.

Nope, pull the stock carb, and throttle cable, then put the fcr on, I used the intake manifold that came with the 38mm and a 1.5"-1.875" silicone reducer like they use for turbo ducting. Mounted perfect!

 

[jasonp]

BTW did anyone else notice the rev limiter in the sound test video?

either that or it's jetted to rich on the main.

 

[duneracerweston]

either that or it's jetted to rich on the main.

Plugs was white after that vid, It does it nomatter the jetting is

 

[Gen1Pat]

No black smoke either on the "surge" , a sure sign of too rich main.

 

[duneracerweston]

It acts exactly like a rev limit, I swear! It dose a little pop of fuel smoke when it does it, its identical to how my 450 acts.

 

[Gen1Pat]

Yeah that's why I pointed out you couldn't see any black smoke. And it did sound like the rev limiter.

 

[Gen1Pat]

Well you would have some fuel smoke cause the rev limiter is only limiting the ignition pulses not the amount of fuel going into the cylinder.

 

[WARRIOR OF DEATH]

dude, where did you get that carb, jw, and how much was it, i would love to throw a better carb on mine to replace the stock one, the more power the better lol

 

[Gen1Pat]

He got it from me, who got it from '00 WO YA!, who got it from someplace I don't know. Read the whole thread and you'll know why he has it now. Since weston has it figured out I'll be getting another. It has worked out well, considering all that I am getting from him. That stuff is worth more to me than that carb at the moment. Can get them off ebay. Just type in 39mm fcr or yfz carb. That is what it is off of. And the stock yfz cable fits, and is ling enough, to reach the warrior throttle housing.

 

[duneracerweston]

He got it from me, who got it from '00 WO YA!, who got it from someplace I don't know. Read the whole thread and you'll know why he has it now. Since weston has it figured out I'll be getting another. It has worked out well, considering all that I am getting from him. That stuff is worth more to me than that carb at the moment. Can get them off ebay. Just type in 39mm fcr or yfz carb. That is what it is off of. And the stock yfz cable fits, and is ling enough, to reach the warrior throttle housing.

Yup yup! :tup:

 

[WARRIOR OF DEATH]

Two things id love to do to a warrior lol, mod a perfectly working kickstart on it, and convert it to fuel injection

 

[duneracerweston]

Two things id love to do to a warrior lol, mod a perfectly working kickstart on it, and convert it to fuel injection

Efi is possible, look in the older threads for small engine efi.

 

[jasonp]

It acts exactly like a rev limit, I swear! It dose a little pop of fuel smoke when it does it, its identical to how my 450 acts.

Yeah if you go up in the main (richer) and find the "rev limiter" gets lower then you know it's a jetting issue and not a cause of CDI. As you go leaner or smaller on the main jet it will do the oppsite. It will be very hard to tune the bottom with such a big carburator and basically no head or manifold mods.

 

[duneracerweston]

Yeah if you go up in the main (richer) and find the "rev limiter" gets lower then you know it's a jetting issue and not a cause of CDI. As you go leaner or smaller on the main jet it will do the oppsite. It will be very hard to tune the bottom with such a big carburator and basically no head or manifold mods.

Agreed, but the bottom is coming together, just gonna take some time.