JD jetting and O ring mod for Yamaha WR450f - Keihin FCR carburetor jetting

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JD Jetting kit:
T-shirt
In this video I show how to jet your WR450f carburetor using JD jetting kit. We will also do o-ring mod on accelerator pump to get you better throttle response. Keihin FCR carburetors are very popular on 4 stroke dirt bikes, you can follow same procedure while tuning this carburetor.

wr450f carburetor tuning
JD jetting kit WR450f

[MOTOBRANDON]

I have a 2005 YZ450F and it ran like crap when I laid on the throttle, I added this same kit along with the large O ring which my bike had NO O ring, and now it runs KILLER. I’m by no means a mechanic and this was easy. I had a harder time removing my carb and dealing with its hose clamps than I did installing this kit. Followed the elevation and temperature recommendations and I couldn’t be any more happy with the results. Thanks!!

[akathecanadian]

These simple tutorials without no BS before during after, amazing. Also I’m running a 48 168

[joshsevens]

I just looked at this jetting kit it is exactly the same as a YZ jet kit you could save a lot of money by buying the OEM jetting for a YZ and then tuning your carb from that jetting and needle jet after the grey wire mod. There isn't any need for the oring mod either you can do the same thing by tuning your fuel mixture screw and needle position and widening your accelerater pump jet.

[v.i.pblack]

Your instructions are easy to understand and your videos are clear 👌 keep it man

[dgtlionbarger]

Thank you for this! This was very helpful, not so much watching what you were doing but your explanation of it all.

[maxpower]

My WR was a monster. Just 60lbs too heavy. The yz cam helped a ton too

[KarlKillers]

I enjoy your 'to the point' and no Bullshit videos, thanks!

[ernesto_yzx]

Brother best video i have watch on this i am new in dirtbikes and have to clean my carburetor on my 04 crf 250r for the first time thank you for your information its very helpful

[mlbushmaster]

Sounds like the rpms drop low and then pick up again to idle speed...maybe slightly rich..cant really tell till the engine warms

[geoffpote]

Great camera work while working on carb, good video overall 👍

[pillcosbyandtheroofies]

Just a heads up that wasn't your accelerator pump, but great video 👍 👌 👏

[MartinJoelsson-sgrm]

Reading that drawing, it looks like you are putting it third from "top"

[fathersun]

Well mine is 450cc / 05 of December, the model .& the problem here is the rpm goes 2 slow after I open the throttle & it stops higher than the normal ofcourse its different when the bike is cold & different if it runs for 5'/10' maximum. But even if i don't ride the bike for a couple of weeks maybe more, it starts with air choke & a little bit up the rpm scroll (sorry for my English)jail lessons. I hope you understand & have an idea how to do it like yours cuz I think we have same model 1year up 1year down 😉cheers 🍻

[Felixx]

Hi. I really enjoy watching your Videos on the wr450. But after all these mods you did to your bike: wouldnt it make more sense to go for the setup recommended for the yz or is the jetting kit made for the wr with these free mods done to it.
Im not trying to criticize you Im just curious:)

[Abitnutts]

Hey mate love your mod vids, a little different here in Australia but a great basis for basic mods. I would love to buy a shirt for my son and I but I am spending all my money on my bike and saving up for one of, the only 400 being built, Aussie Edition 2021 Yamaha WR450F If you are interested in a video on this bike when it is released, and once I have one in my shed, I would be happy to work with you on a video. Keep up the good work champ as I share your passion for the mighty Yamaha 4 strokes.

[divergent]

Since the o ring is really a short term fix before it stretch's, cracks and breaks. Have you looked into r&d power spring or KTM powerparts sxs so spring for a permanent fix? Along with the JD jet kit, ap spring boyesen quick shot 2 or 3 would be total package

[candonic]

I recently bought a 04 wr450f and the previous owner had 48 pilot and a 162 main, I noticed it was lean (I’m at 2000ft btw) so I got this kit and changed it to 170 main, 45 pilot and blue needle on the 3rd position, now my bike seems to run even leaner and hotter. If you could help me out I’d really appreciate it, thanks in advance.

[hillbilly]

You have great videos!! and they are very helpful tips because I bought my first 4 stroke enduro KTM 400 EXC -F -2006 and they use same carburetor in that model. can I ask where do you live? do you have winter over there?? I, m from Finland.

[scottbellisle]

Hey Bud,
That was very informative. I bought that aftermarket carb for my 09 RMZ250 and my throttle cables are different than yours. The lower cable fits in and works, but the upper one has that exact same thread on the upper cable. What year is your bike? I will try to order that cable. I ordered one before and they sent me the one I already had. But yours will fit my carb. Any way to see a photo of your upper cable wit the cover off. This way you don’t have to take the carb off, just the cover. Thanks and would really appreciate your help. I’m not having any luck trying to find the fragile one. But not gonna pay $800-$900 for one from Suzuki.

[dominicpadilla]

Do you have to reject the WR 450 after you do the gray wire and full throttle Mod or is it fine without it?