How-To: FCR carburetor accelerator pump timing adjustment 

probably one of the most informative and easy to understand creators I have watched

This was very, very good. Taking the time to show over, under, and well adjusted, both from the mechanic's point of view and in action, is gold.

You are literally the only person that makes sense on this topic, I have a crf150r and I had problems with bog and I tried everything. Just until I found this, I tried and it my bike runs 110% better. Thank you dude. Really thank you

My old Husaberg FE450 liked this.

You deserve an award for humanitarian aid. Thanks again

Bro I was fighting my 05 yfz for hours before watching this video. You are the man thank you so damn much.

You made my day awesome today. First YT video i opened. Answered my question instantly. THANK YOU SIR. Coz i just bought an old YZ250 ‘06. My very first dirtbike. My 11yo race on his 65cc ktm. 3 yrs now, I fast paced learn how to fix and maintain this lil ripper. I dont have a deep pocket, so we have to rely on diy. Now i got me a dirtbike so i dont have to watch him ride anymore. I tore down this yz already twice, to clean and learn the bike inside out. I noticed this o-ring wrap around that accl pump adjuster. And YOU sir just gave the answer. THANK YOU VERY MUCH FOR THE DETAILED EXPLANATIONS in regards to this part of the carb. Your lessons are priceless. Buying you a dozen of beerz still priceless. Have a great day.

Yes! I was about to ask, what happens if I set up the carb as shown in this video, but my idle is not setup.... I have carb off the bike atm... This was super informative! Many thanks for sharing this!

Thanks Matt. My 2004 wr250f has always had a terrible bog in the throttle. After watching your video and following your steps and adding the o-ring it has made a huge difference!!!!

Thank you! I had the o-ring on but I jumped to a QuickShot, JD kit and different jets, trying to get the bog worked out. After watching your video, turns out that screw was so far out, I was only getting 1/2 a shot of fuel. I adjusted that and got immediate results. The QS, JD and jets did absolutely nothing when I adjusted them. I have a Rekluse auto-clutch and the bike is idling low. I turned up the idle and that contributed to it being much snappier as well. I believe a Rekluse can magnify the bog problem. Thanks for taking time to post this.

You are the man, between this video and the fuel screw video I was able to dial in both my 450r and my wife's 150r. THANK YOU!

I was having crazy bad bogging issues on my 11 ktm 530. Managed to adjust the slop out of the ap using the adjustment screw. Had to look carefully at where the rod that presses the diaphragm sits in the black plastic arm. You can see the slop and find where it is no longer pressing the rod down at all. Absolutely rips now no bog from idle while riding. I am also using the thick o ring from the JD jet kit. Worked great for me without removing the carb from the bike. Only the seat and gas tank.

Two years later and you are still helping motorcycles, my scooter now accelerates a bit better thanks to you haha cheers

Carbs are tricky. Thanks for the help.

I did this with an 06 crf250r I bought for nothing , none one could get rid of the bog . worked 100percent . bog gone runs like a beauty , great video thanks .

Thanks man, I'm a novice to carburetors and that was well explained.

Thank you so much for this. AP pump timing has always been gypsy magic to me and I've been living with the Honda bog for ages. No one really has a good video of this until now so thank you lol

Ur the only one who helped me

This is a perfect instructional video for setting up the Keihin AP. Thank you!

Just want to say thanks for these awesome instructional videos I appreciate your work 🙏

This is a commonly overlooked thing on a modern 4-stroke mx bike with the Keihin FCR-MX Carb. Pretty much all common bike brands use a version of this carb if it's a 4-stroke high performance bike. Very easy thing to check and will minimize if not eliminate any off-idle hesitation or bog. Highly recommend ALL of you to do this inspection. (this as well as clean your dang carb every once in a while - and inspect your pilot jet for blockage - AND never never never use standard ethanol-based pump gas. (Because it can clog your pilot jet over time.)

Thank u. My Wr400f is happier now. And so am I

thank you! i just rebuilt a crf250 and this was the one thing keeping it from starting properly. went from 50 kicks to 1 with one small adjustment!

Thanks man. I definitely learned a lot on these types of carburetors. Since i was used to bikes with no AP's Thumbs up man

Fixed my bike so happy thanks mate

My guy. You saved me and this headache. Thank you for the great video.

This is an awesome video! The temp fuel setup to show the fuel delivery difference is great. Thank you.

Thanks a lot mate, you deserve a billion likes.

FROM DA BIG ISLAND THANK U SO MUCH YOUR VIDEO HELPED ME SOLVE MY PROBLEM I HAVE A 05YZ250F AND WAS REALLY WAS HAVING A REALLY BAD BOG NOW BIKE IS MINT GOD BLESS AND MAHALO AGAIN😉😎🍒🤙

Just did this to my carb on a 06 250x fixed most the bog issue I had once warmed up and ur going u couldn’t tell no more. Plus jd jet kit

THANK YOU SO FUCKIN MUCH!!!! this is a ****** MASTERPIECE!!!! i tried almost every place on earth to calibrate my accelerator pump but nowhere was this clear as this vid!!! MAD PROPS TO YOU MATE!

I subbed! Great video, I wish every video was as on point as this one

THANK YOU! This is the only vid i can find that explains verry clearly how to adjust the accelerator pump! My bike runs perfect now✊😀.

This is hands down the best video on getting the accelerator pump tweaked for maximum performance. Getting that “play” - “slop” is the key! And the Oring is a must. I would also recommend the shorter post diaphragm and smaller leak jet. My crf250r acts like it’s fuel injected.

I'm having to remove my carb to find out why my plastic black idol screw won't turn and while it's off in definitely going to be looking at and doing it if it's not already set up. Thank you

Bravo Matt…Another classic!

The o ring hack did the trick!!! Thanks man!

Awesome! Definitely needed this video! Running into this problem with the yz450f at the moment…

Great video on a much overlooked topic. Thanks, man. Good work!

Very clear instructional video thanks. I'm looking to upgrade my z400 stock carb that's jetted to a fcr style currently running a 170 main and 75 low jets with a Yoshi pipe and stainless header she does good now but I want little more for the hole shot

This trick fixed my issues thank you

Wish my Mikuni TM33 had some apump adjustments on it. Quick opening the throttle like you did has a stutter, and then acceleration kicks in. I'll have to look it over.

Thanks really much for your video!! I gonna try to make this simple mods in my wr250f and kill the bad effect of the bike die when accelerating fast

HUGE THANKS.NOW MY BIKE RUNS AMAZING.👌🙏🙌

Well I went to adjust this, and I couldn't replicate the play you showed so I got confused. Then I realized that the AP isn't squirting at all... Sweet

Thank you so much for helping with theese carburetors, sub for you!

Awesome, thanks! I have this problem ond will fix it tomorrow!

Great, exactly what I need for my 09 yz250f. I'll try it tomorrow

Fantastic video. Thank you for taking the time!

Tomorow i will try, i hope it will work for me.

Very thorough video man. Thank you. Liked, saved, and subbed.

Thanl you so much for the valuable info you provide us !!!!

Thanks for great video! One question, you say squirt time should be 0.8-1 sec, but in you video it's about 0.4 when you say it looks good, so what should I aim for?

Great video. I went to go double check my 05 wr450f’s ac pump only to find out it wasnt even squirting at all. The smaller o-ring under the ac pump cover was totally flattened to the point where the hole was pin sized. Also the brass nozzle it squirts out of was clogged. I un-clogged it all bought an all balls rebuild kit and now it squirts just like this video. Cant wait to try it now and see the throttle response difference. It barely even bogged before also

Thank you so much this made my day

Straight to the point! Thanks Bro.

Well done video. Probably the best one I've seen.

mate....cheers for these vids....bloody awesome...keep it up...some of us get all the info needed...even with the lighting or whatever lol

You saved my life!

nice vid, i appreciate.i like it how you keep it simple and load it with info,you know other channels all seem scripted and have same old info repeated and sometimes more about the presenter.could you know a thing or two or anything about stators?especially winding lighting coil on to stock stator of a dirtbike?

Damn, super great video!!!! Thx a lot!!!

Nice clean explanation, thank you very much!

Great video !!it was very helpful in my wr450f.. Best regards from Argentina

Great! Keep it up!

Spiegato molto bene. Grazie

Great video thanks!

What size main jet and pilot jet would u recomend? Great video thank u!

Very helpful, thanks for a great video!

Wow, thank you so much!

Beautifull video mate! !!!! Many thanks !!!!!

Cheers mate . Your a legend Shout out from brazil

Great video!!! 👍

excellent video. your a pro man.

Very nice video! Gonna try on my 05 wr 450f

Mate you should upload more often !!!

Excellent video!

Just cleaned one of these, for my kx250f. Complete teardown and ultrasonic cleaning. Everything seems good but I have alot of backfire win I get into 3/4 -full throttle and let off. Is that my main jet to big or is it float bowl level. Had a hard time adjusting the float.

This is a great video and I love watching your expertise. I have a 07 yz250f and as soon as I did the o-ring mod it started bogging badly. I took the carb off and my ap arm has no slop in it without the throttle cable rigged up whether it's screwed all the way in or not. Should I just set the timing after it has the tension from the throttle cables?

I tried finding a #78 o-ring and for some reason danco uses weird numbers. For those of you looking a #108 o-ring is the number most manufacturers use it's 1/4 i.d. 3/32 cross section 7/16 o.d. do you know if you can use a #202? Which would be 1/4" I.d. 1/8" cross section 1/2" o.d. if it fits it should last longer?

thank you so much man

Thanks needed just this kind of information...well done...well explained

Thank you man :) you helped me so much :)

Excellent vid! Thanks!!

Merci pour l astuce Ça fonctionne au top thanks for the tip it works at the top 🤙

I have a 06 trx450er with stage 2 hotcams,stock Ferrea Valves,100mm Athena Cylinder with CP Carillo piston and full Barkers exhaust,stock air filter no lid,the acc pump screw was moved around, so I'd like to ask your opinion on jetting and timing screw? Sea level is 105' thanks and great video brother!!!!

VERY INFORMATIVE! MANY THANKS!!!

Mine 150r keeps dying even after this. Should I upgrade my leak jet?

this helped so much. Thankyou!

If the accelerator pump isn’t set up right could it cause the bike to hang revs once the throttle is blipped

sorry for the late post, great video, crf450x ap pump its working ok but squirt duration is too short, i have the o ring mod and the squirt timing is fine. how to improve squirt duration? bike bog on wot and then recover really hard.

THANK YOU

This video helped me a lot thank you. I have the accelerator pump dialed in; however, I still notice a slight bog here and there when just cracking the throttle... and sometimes a hanging idle. Would you suspect a pilot jet being too lean?

Okey so i've done what you did in this video (back in september). I setup the squirt just perfect with just a tiny bit of play. Still my bike bogs when i go full throttle on low rpm. I saw that the idle/pilot jet was slightly damaged tho, On the top were you screw it. It's like a crack. It is btw a idle/pilot jet 45 (Original). Should i buy a new 45 or should i go higher? The next option that i have from 45 is 48. Btw it is a KTM 525sx from 2004. So it is the exact same carb.

Kudos on the tip

Very good video thank you

I know it’s a older video but what does it mean when I turn it all the way in both directions and the slop stays the same?

Thanks!

Would a dirty fmf pipe or clogged pipe have anything to do with spark ?

thank you for the well explain video!

everytime i squirt gas from that little nozle a get a very thin streak and doesnt seem powerful, ive chained the leak jet to a #35 and rejetted my main jet and pilot anf still does the same, what could the issue be? i have a bad bog (just like yours before the acc pump adjustment)