Just curious if y'all can whack your throttle wide open from idle and have it rev immediately without bogging.

nope.

I doubt any bike can do that even with PERFECT jetting.You should be able to roll on to wide open.

first read
http://www.thumperta...0&Number=138644

then read
http://www.thumperfaq.com/ap_mods.htm
and do the BK mod and/or the DOC mod.

jim aka the wrooster
'01 wr250f

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I can, I can!  DOC mod, P-38, and hours of jetting and testing.  Have patience, once you get it right it's pure magic.  the bog didn't bother me much until I rode a bone stock CRF450 and you could wack it like a 2 smoke.  After that I HAD to get mine right.  It was worth all the work.  

I have never had to Whack my throttle open before.  Maybe I dont know how to ride.  Why should I Whack it open?

Mine only bogs on the stand in neutral. I never notice it when riding. I don't race so maybe I never need to be aggressive enough to notice it. When my bike was new I noticed it when riding but a #40 leak jet and a P-38 cured it enough that I can ride with no problem.

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Big doubles out of corners come to mind...

Maybe my bike doesnt have that bog as bad as others.  At the MX track I usually race, there is a turn and a few feet later a double.  My WR has never even hesitated.  

No bog at all, ever.  Clean crisp response on the stand, in the woods ... It's jetting.  Once it is right, you don't have to mess with it.

I've never seen a 4-stroke that wouldn't bog if you twisted the throttle back fast enough. Thats including YZF's, CRF's, and KXF's. It's never given me any problems though. I can still role onto the throttle real hard and usually have plenty power to get those jumps out of corners, but maybe some are worse than mine.

> I've never seen a 4-stroke that wouldn't bog if
> you twisted the throttle back fast enough.

do you own a car?


jim aka the wrooster
'01 wr250f

There's alot of contraversy in here.
Wrooster- some interesting reading there. Will certainly keep me busy for a while.
I'll give it a shot.
Thanks All.

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Yep, no bog at all. Took some work but it can be done.

Well, I don't understand by you guys worry about that because even when I roll the throttle on the front wheel comes up, if I could get it to respond with a "wacking" I think it would just flip over. Just my opinion.  

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Fuel Injection is a little different. My old Cannondale didn't bog either... I guess I should have been a little more clear. But yes, my 84' Chevy Silverado w/ a carburated 350 won't respond right away when I punch it, but then again, my truck is a pile of steaming [@#$%&!].

I'm not sayin the bog can't be gotten rid of... I"m just saying that I haven't seen any 4-stroke bikes that didn't bog if you twisted the throttle fast enough.

Toddly/YZ2fiddyF-
Not really worried about it. But what you're talking about is exactly why I want to eliminate the bog. I just put new tires on my bike and they hook up soooo good now I can't get the rear to break loose without worrying that I'm gonna wheelie. Was playing around the other day thinking that if I could get rid of the bog then I could whack it and know that I'm gonna break traction when and if I decide I want too. Got me curious as to whether it was possible or not. Now it's just a challenge.

I am just an average old guy who used to ride a CR250 when I was a kid, and have just recently bought an '03 WR250.  I am by no means good or competitive, but I must say that the bog sucks!  I was out with my kid last weekend on some hard pack coal tailings (ie really good traction) and I just about got dumped several times because of the bog in 1st/2nd gear.  After that I started to ride it like a 2-smoke and was fine.

I love the bike, and based on what I have read here (and basic knowledge of engines/carbs), believe that the bog can be conquered.  Once ski season settles in another month or two I am going to make it my mission to cure this thing.  I am going to follow the recommendations posted on the FAQ to start with, and will post my progress/setbacks as I go.

For what it's worth.

My 02 nor my 03 had any sign of it. You could whack it till it turned blue and it kept on asking for more.

But both 04's can easily be stalled on the stand doing the same thing. So far it hasnt been an issue riding, and I havent gotten around to messing with it. I will however see what I can do to fix it eventually.

Workin' on the bog on my 03 WR250 with the help of a video camera.  My stopwatch start/stop skills leave a lot to be desired, so I thought I'd use a video camera to capture the event.  I used a stop watch to verify that the camera operated at about 30 frames per second (thanks wrooster).  Then, by playing back the tape you can count the frames, and figure out how close the squirt comes to the slide, and also how long the squirt lasts.

Here is how it came out.  By backing the stock timing screw all the way out, the AP squirt just misses the slide. The slide goes up and the squirt comes out simultaneously. Zero delay.

The squirt duration is .165 sec (5 frames X .033 sec/frame) with a 75 leak jet.  The bike has a slight bog with this set up, but it is much improved over the stock 90 leak jet.  Squirt probably too short.

Then I soldered the stock leak jet closed and installed it.  Squirt duration went to 1.353 sec (41 frames X .033 sec/frame).  This also produced a bog, so here I'm probably too rich.  

Next step, install a 40 leak jet to put me more in the middle of the range and do the 2003 updated BK mod if more fine tuning is needed.  I'll keep you posted if anyone is interested.