Still having bogging problems when gassed!

i recently got a new 07 wr 250 and since day one, when i gas it hard it boggs down till i let off the throttle and ease into it. If i gas it hard and hold it while ideling or in first gear, i can actually stall it. I dont know too much about bikes because of how new i am to it, but i am really trying to learn things myself rather than take it to a dealer. If i need i will, but i would like some advise from some more knowldgeable people than I.

The bike runs fine when i dont gun it and smoothly increse the throttle, but when you have a new bike, you want the power and throttle to be dead on responsive, especially in tight woods and steep inclines. what should i do? So far i have done the air box mod and cut the grey wire if that helps. Thanks for anyone who can help me!

By your description it sounds like you are having problems with your accelerator pump (AP) First you have to determine if your AP is squirting, if it's squirting then the timing of the squirt and the amount of squirt. Try going down on your leak jet to a 60 or maybe even down to a 40. The smaller the jet size the bigger the squirt. Also do the o-ring mod. Your bog can be fixed man!! It may seem impossible but it can be done!!

Read this and hopefully it helps

From the sound of your problem, it is most likely the AP.

But if you modified the airbox, you should check your jetting, especially the pilot circuit. William has good instructions on how to set your fuel screw and you can find them without much searching. You could also try turning the fuel screw 1/4 to 1/2 turn out and see how it runs.

your pumper should squirt fuel when you crack the throttle open suddonly... it's a finicky part of a carb and requires a lot of tuning to get right

wr's come with bad jetting for better emissions and what not.

non race dirt bikes usually come with vacuum operated slides that don't open fast so this doesn't happen

No one rides at idle than goes WFO. Ride the bike normally. Do not try to force the bog. Anyone can force a bog on any bike.

Try the oring mod for starters.

thanks alot for all the help guys. since i am not that good yet messing around with the bike, would you all suggest that is something that it worth taking to the dealer? About how long will something like that take to fix? it sounds like alot of trial and error and i am not looking forward to opening up the carb and all that as well.

and what exactly is the O-ring mod?

As far as taking it to the dealer, it depends on how much confidence you have in them. Some dealers are terrific, have mechanics that know what they are doing, sadly it seems most have mechanics that often make matters worse.

O-Ring Mod and AP Tuning

The o-ring mod is definitely something you can do. Very very simple

OK, ill try it today. One more stupid question.....How exaclty do i get where i need to be in order to do the o-ring mod? Thanks for everyones help!

Not following you.

To answer you bluntly, on the right side of your bike. I would suggest walking there if you are home or driving if at work or another place not within walking distance :ride:

Doing the mod is a simple, five minute job, ten if you have no idea what you are doing.

Right side of the bike,Using an allen wrench, remove the cover on the side of the carb. Work the oring on, put the cover back on.

The links should show you exactly what to do and how to get there

No one rides at idle than goes WFO. Ride the bike normally. Do not try to force the bog. Anyone can force a bog on any bike.

Try the oring mod for starters.

you shouldn't be riding at idle anyways... when you goose the throttle off idle it's the worst bog you will see.

if you have bad bog when riding it will ran bad for a second and clean up and accelerate. getting that throttle response back is what you should be tuning for, not idle.

when I had a 250, 450, 600, 1000 I went from engine braking to WOT a lot. more so on the lower cc bikes.

if you have the accelerator pump tuned correctly, you should be able to brake into a turn, get out of the turn and go WOT without any hesitation.

if your stuck having to slowly add throttle that just sucks and is no fun, ive been on bikes like that and when I nail the throttle it bogs so bad I hit the bars then it takes off... no no no.

after the O-ring is in place, what exactly does it do or prevent? It seems hard to believe that such a small and simple thing can have such a dramatic impact but that is comming from someone who really has no idea what he is talking about haha

Takes the slack out of the squirter :ride:

^^^ what he said

and if that isn't detailed enough, it helps squirt the fuel in quicker...

when you get better with tuning, you can try different diaphragms. on my old ktm, I ran the honda one and it did wonders...

pumper tuning is huge for me, but I like to wheelie over stuff

Hey Guys

Since Im in the process of doing my FCR mod, I was looking around for info on the O-ring mod. It seems like there is only one proper pic of this mod on the whole forum, trust me, I searched!!!

Therefore I took it upon myself to add some more pics to the topic. I just want to feel like Im helping and not always asking for help…:ride:

Anyways, I did an O-ring photoshoot for everyone.

I took the size that William1 gave in one of the threads and converted to mm.

Went to the hardware store and this is what I got:


And installed:


And 2 close-ups:



This really is a simple mod, not in the realms of quantum physics and cold fusion, like I thought.

Took me all of about 2 minutes to do.

Group Hug :lol:


This should help you out. I didn't notice much difference when I O-Ring'd my YZ but a JD Jet Kit really made a difference in the bog. Have you done anything other than the air box and grey wire mod? If you're local, I have a silencer you can try and see if it helps.

Thanks alot guys im gonna try to work thru it myself as much as i can and see if i can at least improve the bog

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