Carburetor Screw... I guess my '08 doesn't have one?

[701yamaha]

I have been reading about "bog" etc. and have read that some mention of adjusting the fuel screw. I can't find mine, I don't see anything in the manual or while physically looking with a light. Does the 2008 not come equiped with one?

Another question I have is about the needle clip. Can I remove the needle from the carburetor without carburetor removal?

Thanks,

[mkporn]

the screw is by the throat of the carb, between the cylinder and the float bowl. if you look at the float bowl you will see a little bump out and a hole in the front of the bowl closest to the cylinder under the carb....it takes a special length and size screwdriver (most times you can get a thin stubby to work or a long standard screwdriver bit).

You can remover the needle without removing the carb. Take off the seat and tank and you will see the top of the carb. remove the 2 allens and the top comes off. with another allen, remove the screw that is dead center in the slide and you will see the needle down in there. use a pair of needle nose pliers and remove it.

[701yamaha]

I will look this afternoon, sounds like a tricky location. I have seen the top of the carb from between the frame when I had the tank and seat off, I just wasn't sure if it was possible to remove in through there.

Thanks for answering those questions,

[RocknRod]

If you have a wr250f, there is a plug in the float bowl that need to be punched out first. You must remove the float bowl to do this. I had to remove the sub-frame and upper motor mounts and shock to do this. It wasn't as bad as it seemed, but if you are gonna go through this I would recommend buying a jet kit or maybe even a rd powerbowl since it is quite labor some. The needle on a wr250f is non-adjustable so that is why I recommend a jet kit. Gytr, JD Jet, FMF and dynojet are a few jet kits available. I am not sure if any of the other free mods have been done such as the grey wire, removing the plug from the exhaust and the snorkle from the air box but these would compliment the jetting changes. You won't be dissappointed........RG

[701yamaha]

The bike is brand new, I have put only an hour on it so far am and waiting on an oil filter dilevery so I can do the first oil change. I have removed the grey wire and pin from the CDI, Removed the plug in the exhaust, and machined the throttle stop down to YZ specs.

Once the bike is warmed up, it will idle fine but bog heavily when the throttle is applied quickly either in gear or in neutral. I have even opened the air box lid to see if that helped; it didn't. Keep in mind the bike did this even before any mods were done. I don't want to mess with the carb until I have a few more hours on it and its fully broken in. Either way, I would like to get familier with it beforehand.

[jffsnlsn]

Have you read through this sticky? If not, it is worth the time.

https://www.thumpertalk.com/forum/showthread.php?t=54475

After reading the sticky, you should then try searching, prior to posting.

Some of the newer bikes don't come with a fuel screw.

Bogging in the garage is irrelevent. Does it bog, after warmed up, during normal riding?

If so, bog is usually cured with a 40 leak jet & merge AP spring.

[YZEtc]

If you've got a new (2007-2009 model, I assume) WR-250F, I can guarantee you that your carburetor has a fuel screw.

As stated a few posts above, there's a plug pressed into the hole where you'd stick your stubby screwdriver in to turn it.

This plug is put there to prevent you from tampering with it, to be a good tree hugger, and to not be allowed to ride your motorcycle with something resembling performance.

Bottom line:

If you expect to get your $6,000 worth of performance, rejet that carb with one of the readily-available jet kits - pronto.

It's not going to run right with the stock carb settings.

Don't wait for a break-in period to be over with or any silly reason like that because that won't amount to anything with the longevity of your engine.

You will be wasting riding time, though.

I went with the Yamaha GYT-R AIS removal kit, which comes with it's own jet kit.

My bike runs worlds better. ?

Do it.

By the way, I've rejetted my carb on my 2009 WR-250F without having to remove the carb from the bike at all.

Yes, no subframe removal and no wrestling with trying to squeak the carb past the frame spars.

The float bowl (bottom of the carb) is held on with allen-headed screws, as is the top cover and the right-hand side cover over the acellerator pump.

All of these parts can be removed without taking the carb off the bike.

[700driver]

So I put a pipe on my 06 WR and needed to adjust the fuel screw. Referencing my service manual the diagram didn't show one. After taking the bowl off, low and behold, there it is. I don't know if this is an error in the manual or if it's in other years as well but sure enough the screw is there.

[701yamaha]

I spent some time on my bike over the holidays. I installed the GYT-R AIS removal kit, brake switch, installed some DOT tires, and made up a wiring harness for all the required DOT electrical items. I ran turn signal wires as well so they may be added if I feel the need. I am now bending up a licence plate/ blinker bracket.

Changing the GYTR jets out is not a problem with the carb installed. It may have taken me 30 minutes at a leisurely pace, though it is a little fiddly. Very simple to knock the fuel screw plug out. I have only driven around my short driveway with the new jets intalled and I seems to get up on one wheel easier now.

I have yet to drill the additional 1/2 hole in the second baffle, I won't add noise if there is no power to be had.

Thanks for all the assistance,

[YZEtc]

I have yet to drill the additional 1/2 hole in the second baffle, I won't add noise if there is no power to be had.

There is definately power to be had by doing something about the choked-up stock muffler.

Why do you think it's so whisper-quiet?

I ran the bike for a bit with the hole drilled in the second baffle of the stock muffler, but the bike still felt like it had a potato stuffed up the muffler.

I installed an FMF Ti-Q muffler along with an FMF Powerbomb head pipe, and the difference was pretty impressive.

Noise is more than the stock one, but anything else will be because the stock one is restrictive - that's a side effect of being whisper-quiet.

The noise of the FMF ain't too loud, though, and completely acceptable to me, and I'm a guy who frowns on rediculously loud off-road (or street, for that matter) bikes.

Put it this way:

If I smashed the FMF exhaust that's now on my bike to the point that I had to get a new exhaust system and a stock one was available to me for free, I'd choose to buy another FMF (or whatever brand you might favor) exhaust.