06 yz250f bogs down.. any ideas?

[rolloutjg]

my 06 yz250f bogs down, when i really get on the throttle from idle. if i slowly rev it up, then i can get on it all i want. its just those first few thousand rpms. any ideas?

thanks,
sore left wrist

[ept250rider]

my crf450r tends to do the same sometimes but usually if i clean the air filter and clean/replace the spark plug it snaps just fine. being my first year with a 4 stroke, and the weather getting cooler, it bogs when the engine is cold but if i let it warm up i dont have any problems. it could be a jetting issue but i dont know enough about jetting to give u any pointers on that stuff

[Woody_393]

First off I'm a bigger guy, and I don't normally ride a 250F, but when I do, I see the same thing.

I see your solutions as follows:

1) clutch it so it gets more into the meat of the power
2) Get a JD Jetting kit so you know your jetting is spot on.

[Budlite]

leak jet....go over to Thumper Talk and do a search. you probably need around a #50

[ktm_cody_199]

The yamie already has a leak jet,You have the same problem I had so here is a link to the whole thread and here is your solution.LINK:PLEASE HELP(jetting issues) Jd jet prb

truned out when I put my jet kit in I had the ACP pump spring in upside down holding the diaphram down and I wasnt getting squirt.But your solution would be a JD jet kit:[Only registered and activated users can see links. ]

Youre also ganna want a fuel screw so here is a nice one:
[Only registered and activated users can see links. ]

install the jet kit and tune the carb with the fuel screw and your 250f will have perfect throttle response,you will wonder why everyone doesn't do this its that easy

[pjg351]

Originally Posted by rolloutjg

my 06 yz250f bogs down, when i really get on the throttle from idle. if i slowly rev it up, then i can get on it all i want. its just those first few thousand rpms. any ideas?

thanks,
sore left wrist

Welcome! Talk about deja vu, yes i had an 06 yamaha slug the same as you, the most gutless bike we have ever owned, i had some success changing the accelerator pump to a boyseen, this improved the bottom end performance, and i wasted a lot on a PC pipe and jetting hoping to ignite the top end more, no such luck Good luck with it.

[rolloutjg]

hey cody thanks, sounds like it should work. i'll definatly give that a try. (im deployed overseas right now, but i wanna get it fixed soon as i get back) any idea where i can find a tutorial or something on jetting? ive never even came close to attempting this.

[ktm_cody_199]

No need for a tutorial,ATM and JD jettings got you covered It comes with well detailed instructions and pictures so you will be fine.The boyseen QS2 might help some too but nothing makes as big a difference as a jet kit.If you really want to go nuts,get a R&D power bowl.I never tested one before because it goes against stock class rules,but I hear nothing but good from the guys that have them:[Only registered and activated users can see links. ] made by the same guys with the easy adjust fuel screw

[ktm_cody_199]

O forgot,let me be the first to thank you for serving our country

[rolloutjg]

no problem.. im just ready to get stateside and ride lol.

since it idles fine, and only bogs down in the low rpms, my main jet & pilot should be fine right? i should just have to adjust the slide??

[rolloutjg]

if i installed the powerbowl, that would eliminate having to adjust the jetting? or would just make it easier?

[ktm_cody_199]

You will still need proper jetting to get best results out of any mod you do to your bike.The powerbowl just keeps the fuel up closer to your jets and makes it alot easier to tune the squirt.This way you dont need to pull the bowl off to change the leak jet because it is adjustable.You can easily adjust whether you want more or less squirt with the turn of a knob,just like the idle and that fuel screw adjustments.If your on a budget then get just the jet kit and a fuel screw and it will improve your Throttle response significantly.

[ktm_cody_199]

Here is a good pic that will help you better understand how the ACP/leak jet works,cant remeber where I found it
See that little jet labeled "leak jet" that meters some of the fuel off to the float bowl so that all of the fuel doesnt go into the AP nozzle so you dont get to much squirt.Bigger leak jet,less squirt.The R&D float bowl has an adjustable leak jet so you can adjust how much fuel is blead off back into the bowl.

EDIT:never mind,here is the site [Only registered and activated users can see links. ]

[Yves Edge]

There is a AP mod you can do to it. 50-55 leak jet works good on that. If you safety wire the arms where you adjust the duration for the AP under the side cover on the carb together, so when you twist the throttle you don't have to wait on the spring to catch up one arm to the other. It will give a better squirt. You want to make sure you adjust the set screw so it just meets the other arm at wide open throttle before you wire them together so your not binding them when you wide open. Guaranteed to fix the bog as far as the AP!