05 WR250F Bogging

[woodiboyd]

I need some help. If I get on the throttle from idle I get a horrible bog.

05 WR 250F

I just installed a Jardine full exhaust

disabled the grey wire

removed snorkel and cut out the side knockouts in the airbox

installed powernow and powernow plus

installed MSR fuel screw

installed JD jet kit. - started with 185, blue @ #5, and stock pilot. After reading some threads I tried a combo that was posted by someone who had a similar setup and environmental conditions - 180, blue @ #4 and stock pilot.

I am in the Seattle area and generally ride in an elevation range of Sea Level - 2000 and temps from 50 - 80.

I have adjusted the fuel screw with no luck. Any suggestions would be greatly appreciated.

WoodiBoyd

[rynomation]

I had the same problem on my '04 wr. Thanks to the search button & a JD kit. Problem solved. Try a #40 leak jet. (stock on mine was #70) I am at 5000-9000 alt. in Colorado so my jetting is Red needle 2nd clip, 175 main 2 1/2 out on mixture, o-ring mod. I started out on the 3rd clip but it was still a little hesitant when wacking the throttle. My first day out to test I was grinnin ear to ear. I only wish I had done the jetting before I went on my first trip to Moab, when I bog-stalled out on just about every up hill tech section. Thank you magic button! Good luck.

[Wideopen24_7]

The problem most likely lies in the pilot jet and fuel screw but you still should get a #40 or #50 leak jet. First disable the ACV and learn to set the fuel screw by the sound of the decel popping. Its really easy and you can do this during a ride. Crack the throttle hard for a few seconds and when you let off the gas completely then listen for popping. If you have none then you are too rich. For this turn the fuel screw in a 1/4 turn, ride and listen for pop. If no pop then repeat. When you start to hear the pop then thats where you want to be. If you keep turning in and there is still no pop then try a 38 pilot and start over. Anytime you ride your bike and you have no pop then turn your screw in until you do. Now, anytime you ride and you have decel popping then you need to find out how far you are from not having any. The key is being right at the point where you have pop and no pop.

[jpfire]

Woodieboyd, keep us posted on what you find out with your jetting. And how do you like the Jardine exhaust? (power, how loud, easy to install) I was thinking of getting one but not many reviews to sift through. Thanks JP we-

[woodiboyd]

Thank you for the great information. I stopped by the dealership on the way home last night to pick up a couple of leak jets. When I got home and read through my manual I found out that they actually gave me pilot jets so I am heading back down today. At least I can tell the difference now.

The Jardine exhaust and header was very easy to install. The only area that was a little frustrating was attaching the exhaust can to the subframe. The provided bolt was just a tad too short with the spacer. A new bolt solved the problem.

The Jardine definately has a more throaty sound to it than stock but it does not seem to be any louder than pulling out the stock baffle.

Power wise I have not had a chance to really get a feel for it. Hope to get out in the next couple of days.

[barton]

Thank you for the great information. I stopped by the dealership on the way home last night to pick up a couple of leak jets. When I got home and read through my manual I found out that they actually gave me pilot jets so I am heading back down today. At least I can tell the difference now.

That's pretty common. The parts monkey often doens't know what a leak jet is, or where to find it. It's best to take the part numbers with you and say, "I need this part number." The less you tell him, the better chance you have getting what you need.

Here's the part numbers for a few leak jets.

35 leak jet: 4JT-1494F-01-00

40 leak jet: 4JT-1494F-03-00

50 leak jet: 4JT-1494F-07-00

You can find other commonly needed part numbers here: http://www.thumperfaq.com/yamaha_oem.htm

[j d]

That's pretty common. The parts monkey often doens't know what a leak jet is, or where to find it.

So effectively your saying that a Yamaha Parts Interpreter is really a title for a "MONKEY". I'd tend to agree.

[docthrock]

I'm happy to report that I have the bog in my 2005 WR250F under control. I went back and double checked my JD instructions, then searched TT for other's results. I still haven't had to change the leak jets (maybe there's already a 40 in there?), but I have a set of them on the way. I bought the next 5 larger sizes (for about $5.50 each) from a Yamaha dealer in Fargo (University Motors).

One thing I have noticed is that I have to warm the crap out of by twofiddy before I can even think about evaluating the bog.

Last year, I would get in a tight spot when the bike was plenty hot, have urgent need for power when near idle, die and keel over. That sucked. Now, though, after adjusting the red screw all the way in, then back out, and the JD jets set for my area (blue, 500 ft above sea level), I got NO problems whacking on the throttle. SWEET!

Now if I could just learn to ride the darn thing....

[dirtbeater]

So what do you think of the jardine as far as performance?

[woodiboyd]

Update:

I installed the #40 leak jet and went out this weekend. Problem solved! My bog was gone!

With all the free mods, powernow, JD Jet Kit and the Jardine exhaust this bike is fun to ride.

Many have inquired about the Jardine exhaust. The exhuast is very easy to install. I did notice a nice improvement in power - the noise level is not too bad. A buddy installed a Jardine on his KLX and it is actually quite a bit louder.