250 RFS Transformed

OK, went out to a practise enduro track yesterday to try out all the latest mods to my 2002 250 EXC Racing.

Jetting as displayed in my signature is spot on. It pulls from nothing really hard, is very controllable on part throttle, like another bike really. If KTM had this jetting when the bikes were tested by the UK magazines they would have sold a whole lot more motorcycles.

The other mod I hadn't tested was the Fabtech fork revalve. I'm very impressed. The bike was always quite quick steering, but the front end was never planted, and drifted wide on flat tight turns. It doesn't do this any more. Also feels a whole lot less harsh across roots and sharp edged bumps. Coupled with the better throttle control it's about 20% faster in the turns.

As for the heavy clutch I complained about - the jetting means I hardly use the clutch, so the weight of it is much less of an issue.

One of the guys from a local dealer had a ride. He's fairly experienced on a good variety of machinery, and reckoned it was the best woods enduro bike he'd ever ridden. I take this as a very serious complement for the bike.

It ever so quick now too, and picks the front wheel up easy. Better go away and learn to ride now, I just ran out of excuses!

Liam

From where did you buy the DXM-needle? I`ve tried to find a dealer here in Sweden but noone can or will help me here! I`ve replaced the pumpdiaphragm and the only thing that I miss is the needle that I can`t find over hereso a little help with this would be nice !

Jonas

Isn't the OBDXM at mid clip position equal to the OBDTM in the top clip position?

Belse,

The needles come from Yamaha. Part numbers I got from James Dean were:

OBDXN is Yamaha part #5GS-14916-DN-00

OBDXM is Yamaha part #5GS-14916-DM-00

My Yamaha dealer got them in by the next day without problems. You will be so impressed by the difference. It's like riding a different bike.

RMCCool,

Yes, a DXM in the middle is the same as a DTM in number one. Only problem is that when the weather gets hot it'll be impossible to weaken the DTM, whereas the DXM will still have a couple of clip positions to go, which to my mind makes it a better choice.

Liam

Liam,

I'm glad to hear the new jetting is working great!

---------------------

Please note a correction to the post above about DXM/DTM-

DXM in the THIRD clip position is the same as DTM in the TOP.

DTM#-- = DXM#2

DTM#1 = DXM#3

DTM#2 = DXM#4

The DXM is a "standard" European Yamaha WR400 carburetor needle from 1998-1999. Get it from a Yamaha dealer outside the US using the part numbers Liam posted.

OBDTM is a "standard" carburetor needle from the '00-'02 KTM RFS 400-520 models (non-Calif.) and also the US-only 1998-1999 Yamaha WR400.

OBDTM is Yamaha part no. - 5BF-14916-DM (available at Yamaha dealers in the US)

These are NOT AVAILABLE AT SUDCO OR CARB PARTS WAREHOUSE.

James

Also worth noting that in the UK needles are about 20% cheaper from Yamaha when compared with KTM, so get them from Yamaha if you can.

Liam

James,

It's taken sometime but I have got around to changing the jetting on my 250 rfs. Getting the carb out was easy as well as changing the accelerator pump setting, the jets and needle (I'm a novice when it comes to messing around with bikes but I'm learning fast ? who says you can't teach an old dog new tricks).

I took her out for a quick spin and what a difference, as Liam says it just comes alive, its like different bike. I also agree with Liam that if KTM had supplied a 250 rfs with this jetting it would have got a better write up in the trade mags.

Many thanks for the advice James and if are ever in the South East England then look me up as I owe you a pint, beer that is.

Taz

:)

It's great to see the change is working for you too! :)

A quick follow-up on the OBDXM needles. I received OBDXM and OBDXN needles from Clearbrook Yamaha today! (B.C., Canada). This is a NON-US part that must be ordered from NON-US Dealers.

If anyone wants the DXM and DXN, they are available from Canadian, UK, or Australia Yamaha dealers. (DTM#1 = DXM#3, DTN#1 = DXN#3)

US riders can call Clearbrook Yamaha (BC) at 1-877-811-0011 (toll free) and ask for Randy. He will order the needles from Yamaha Canada and ship them to you. They are now available as a special order item.

( Clearbrook Yamaha open Tues.-Sat.)

OBDXN is part number 5GS-14916-DN

OBDXM is part number 5GS-14916-DM

Hope this helps a few 250RFS owners.

James

What comes stock in the 2002 KTM RFS (M/J, A/C, P/J, needle, and the pump stop membrane)?

Stock for the euro (uncorked) version:

Main - 160

Pilot - 48

Main air - 200

Idle air - 100

Needle - OBEVP in #6

Stop pump membrane - 0

Stock for the resticted markets

Main - 160

Pilot - 45

Main air - 200

Idle air - 100

Needle - OBEVR in #6

Stop pump membrane - 0

Slide stopped at 24.5 mm (10 mm from full open)

HTH

Liam

My bike was original purchased in Canada so which category does it fall under.

Thank you for all of the help.

I know my 250 had:

Main - 160

Pilot - 48

Main air - 200 (didn't check)

Idle air - 85 (I'm pretty sure it was this one I pulled)

Needle - OBEVP in #5 (#4 is preferred close to sea level)

Stock jetting was all over the place with these bikes and I think they made changes all through the production run.

my 2003 came with a 43 pilot - not sure about the other jets. Replaced the 43 with a 45, made a big difference. Also, after 2 hours the dealer checked the valves and they were too tight - he thinks they probably came that way from the factory.

Ted

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