[SlammedRanger]

Well guys and gals i decided to do the fcr carb upgrade on my 07 416ex this winter. With alot of talking back and forth with moose @TRX2fiveO i decided the yfz fcr 39mm was the way to go. So i made my purchase of a 08 yfz450 fcr39 that seems to be a very low hour carb.

Positives- already has zip tie mod-already has r&d flex jet-low hour-very clean and taken care of

Negatives- 275.00 shipped...........gulp!

 

[SlammedRanger]

After alot more talking with moose @TRX2fiveO about a jetting starting point we decided a 38 leak jet a 170 main and a 50 pilot is where i will begin.

This is where the crap hits the fan. I recieve the carb in the mail and it looks great! I find that the leak jet that is in it is clogged. No biggy it needs replaced with my 38 anyway. Try to remove it and boom strips the flat tip slot right off............dang this is where i figure this is going to get expensive. Lucky me i find a fcr bowl for 21.00 shipped. Needles to say i couldnt click buy it now fast enough.

 

[SlammedRanger]

The fcr39 carb fits into the stock engine side boot with some heat and a solid push it will go.

Now since i just finished the install of this lastnight and its fresh in my mind i am going to give a run down of everything needed for this to work.

-The fcr carb is to tall on the throttle linkage side and it has a casting of where the push cable would be on a dirtbike. You need to grind that down about 1/2 to 3/4 of an inch

-you need a yfz450 throttle cable(i went with a +2 inch one)

-5/16 fuel line(you will also have to cut off a casting piece on the tps side of the carb for the fuel line to have clearance.

-a fernco connector for between the carb and stock intake boot.(Airbox side)

-i highly recommend the r&d flex jet

-a few small washers to space the gas tank base plate up a few thousandths

-quite a few different sized clamps

-i also cut the intake tube and slid a piece of 2 1/2 od stainless exhaust pipe connector between the fernco and stock intake tube. Thanks to @stang9gt i think it was that posted that nice write up on how to do this.

 

[SlammedRanger]

Now here are the installed pictures minus the airbox that is because my subframe isnt back from being modified yet.


*I also threw a sneek peak of my subframe that Josh from Mud Motorsports did for me*

 

[SlammedRanger]

Now here is something with all my research almost no one covered. The fuel line. This was a big pain to squeeze in there. The petcock nozzle almost contacts the carb directly. With the removal of the casting piece on the tps door it helped alot. I also added a spring to the outside of the line to keep it from kinking. Helped being an appliance repair tech because i have springs of every shape and size lol. I havent started the quad yet but it is fully installed and waiting for the subframe. I will update as i start the tuning process and then i will update again this spring when i can feel the power difference. Stay tuned everyone!

 

[SlammedRanger]

Its alive!!!!!!!!

Idling alittle low and the slide is rattling a bit. But she started right up in 19° with the choke and idle perfect. Something literally unheard of in a 400ex. More tuning to come but atleast its making some noise now haha

 

[XplicitRacing6]

Holy cow its a miracle lol... tired to start mine today..... 13F....she did not want to start so I put her away lol

 

[SlammedRanger]

LoL yeah i couldnt believe it fired up that easy. I have never started a 400ex so easy in that kind of cold my entire life. That starter jet really does the job well lol.

 

[XplicitRacing6]

I eventually got mine going but I had to heat her up.... once she fired she sounded mean lol..... I went and started my 1999 300 and it fired up instantly with no choke and no throttle

 

[SlammedRanger]

Well guys and gals. The weather here finally warmed up enough for me to go for a ride and not freeze my you know what to the seat. It was 60 degrees ish today. So i took the quad out for a rip. And sad to say it but honestly its slower..........i know its just a tuning issue. So the 170 main is a no go. She fell flat on her face at wide open throttle. My next step is bumping the main up to a 180. And we will see where that puts me. I have to imagine this weather will break and go back to snow pretty soon so i wont be able to update until then. But let the tuning begin!

 

[XplicitRacing6]

Sad to hear. Don't give up!

 

[SlammedRanger]

Dont worry i dont give up near that easy haha. I did i think find why i was having issues though......feel pretty dumb lol.

 

[SlammedRanger]

Not 1/2 kinked not 3/4. All the friggen way kinked lol

 

[SlammedRanger]

This should fix its little red wagon. LoL

 

[XplicitRacing6]

Agh man. I've done that before. My cheap a$$ tried to bypass that S fuel line going from the petcock. With a straight piece of tubing. Didn't work lol

 

[SlammedRanger]

Well still to cold/snowy/rainy to ride it again. But i did fix one problem i noticed right away when riding it the first time. The throttle was way stiff. I would have cramped my thumb in 20 minutes of riding the way it was. I did alot of research to find im far from the only one with the problem and it was a huge negative alot of people had when getting the yfz. So with that there are multiple options for fixing the problem. Tokyo mods makes a lighter throttle cam spring for the fcr carb. You can change the indexing of the factory spring with drilling a small hole in a spot on the cam wheel. Or moose makes an ez pull throttle housing. I did the last option. I liked the idea of a longer throttle lever anyway and i will say it works perfectly. The throttle push is as easy as the stock 400ex was now. And i always have the option to add the tokyo mods spring later if i want it even easier. I cant see needing to but its an option. Thats my update for now. Lots more to come when tuning starts im sure.

 

[SlammedRanger]

So last weekend it was finally warm enough to take it for a rip. And i must say the difference was well worth the effort. I was fighting the front end down just cracking the throttle in 3rd gear. It ran really well over all. But i noticed when going down the road it was flat at WOT. Didnt seem to pull near as hard up top. So i did a quick plug chop and confirmed its lean at WOT. I also noticed that the more i rode it and the more i adjusted the mixture that 3 turns out was best throttle response, idle, and starting. But im going to ignore that for now and focus on getting the main jet dialed first. I pulled the plug when i got home and was so relieved to finally have color on a spark plug. Since for some reason no matter what i did i couldnt get any color on a plug with the stock carb. Let the tuning begin!

Current jetting 170 main, 50 pilot, 38 leak, needle clip one down, mixture 3 turns out

Feel free to chime in and brain storm jetting suggestions

Me and moose both say up the main jet for starters 180-185

 

[retro]

I agree, I'd try 180 in the main next if the air temp ever gets above 50 degrees again.

I'd give a 180 a hot motor fightin' chance at WOT... see if I could make it stick or not. If you like it put the bigger one in it and take notes... you'll need to bump up on a cold race night sooner or later... may as well be prepared.

You are getting close once ya got some color. Jetting sessions are a lot of fun, take lots of notes!

 

[SlammedRanger]

Thanks for the suggestion retro. I kinda went balls to the walls lastnight and put the 185 in lol. Next 50 degree ish day im gunna do an actual plug chop and see where that puts me. Got 4 dpr9z plugs so hopefully i can get it dialed in that many tries lol.

 

[wheeler]

Glad to see you have it running. Jetting on something like that is most defiantly a nightmare as someone else may have the same set up but live at a different elevation which makes tuning hard! My new to me 300ex carb showed up yesterday. Once I get it cleaned up and make some educated guesses on what jets I should start with, I'll be in the same boat as you!