450EXC jetting

[MCassle]

Just bought a new 03 KTM450EXC, but I suspect that I need to rejet the carb as the pipes are blue & this is a CA model, so I think it may be running lean off the get go.

Any other 450EXC owners have some suggestions to proper jetting for this particular bike?

I did a search for this info & came up empty ...

Thanx,
Matt

 

[mrmodine]

Not alot of jetting info in this forum lately.

Try this:

OCEMN needle in the middle clip
172 main
Stock pilot
1 turn out on the fuel screw

OCEMN needle is the best on these bikes from everything I have read and it works great on my 400 too. You can get it from Mike at CycleZonektm.com.

If you can't get the OCEMN needle, you can probably richen the needle a couple clips on the stocker and get it to work.

 

[fremontguy]

Congrats on the new wheels. At 3k elevation, I've had good luck with DMN#2, 42pilot, 170main. EMN#4, 42p, 165m. Didn't like stock jetting, only tried that 5min. and thought it would melt down from leanness. Fun bike.

 

[MCassle]

Thanx for the suggestions guys :)

I've changed needles in the past, but have never changed a pilot or main. Is this a no brainer type job, or are there some pointers you could give to me? I read the manual and didn't see any reference to changing these components in the carburetor.

Thanx,
Matt

 

[fremontguy]

I've swapped main and needle on 450e. Just remove seat, tank, shrouds. Loosen carb boot clamps on both sides and pull some slack on breather hoses. Drain gas from bowl using screw in bottom of bowl. Twist carb to right, use 17mm wrench to remove lower bowl cap to access main jet. Take off top cover to access needle. Twist throttle bringing needle up, take out needle holding screw, pull out needle. Hope this helps, could try #5 or #6 position on stock DVR needle for better performance.

 

[placelast]

Matt: I can help on the wrenching this Friday at the Clear Creek camp, if you'd like. Heck, I've become a part-time wrencher with the two bikes I've been working on, and bring all my tools, so it's no big deal; the two of us can make quick work of it so long as you have the parts (and spares if we drop/lose any).

If your KLX is for sale then you and a friend from LA should talk pronto - after the Boar I am driving to LA and would drop it off for you/him (so long as you bring it to Clear Creek) to close the deal, but that's only if you want to sell it. Look for an e-mail tonight on the subject.

 

[Jonala]

Matt,

Congratulations on the new bike. I hope that rocky trail climb that we went up had nothing to do with this purchase. As I remember you were very high on your KLX.

Fremontguy rides all over N.CA non-stop only to take a smoke break. So his jetting specs are probably right on. :thumb:

 

[fremontguy]

John, if you can come down with a sudden case of dirtaleptis flu tomorrow, come on up to Stonyford for some riding:)

 

[Jonala]

Les,
Thanks for the invite, but I have to save my energy for this weekend. I attempting to ride the Wild Boar this Sunday. :scream:

 

[MCassle]

Thanks for the advice Fremontguy, I appreciate it ;) I called the local dealership where I bought the bike (WilsonsMC), but they do not carry any carb parts for this bike, sheesh. When talking to the mechanic about what he would suggest for proper jetting on this bike, he was 180 degrees off from what other 450EXC owners are telling me, so I'm pretty much done dealing with the local shop. They seem more interested in the street line of motorcycles.

From the suggestions of other KTM owners at KTMtalk.com, I contacted www.cyclezonektm.com in Kansas for ordering parts. I ordered several mains (175, 172, 170) and a pilot (45) in addition to the OCEMN needle. I went ahead and purchased the Fuel Screw Extension as well. From what I've read on the subject the fuel screw is a bugger to access on the 450EXC, I think due to the electric start. Anyway, thanks for the offer John but I seriously doubt these parts will arrive before the big weekend. I'll have to hit you up on that offer at a later date.

Jonala, I believe that was a rocky trail descent, lol. Naw, I've been thinking of getting another bike this past year or so, I'm a bit big for the KLX. I love the bike, and at this time I’m not going to sell it unless the wife really starts giving me grief, or I’m hurting on making the payments for the new bike ;)

My thoughts were I could pour money into the suspension and a 331cc kit for the KLX, or just get another bike. Opportunity presented itself & now my bike is orange :) Hope I can handle the power, I think it is going to make the KLX look like a cheap date!

Matt

 

[mrmodine]

Matt: FYI the fuel screw is a bugger on these bikes...all the RFS' for that matter due to the Keihein FCR carb...the fuel screw is deeply imbedded in it. I think the Yamaha F's have the same carb and same problem so these fuel screw tools are getting common.

 

[MrLuckey]

Be careful with the fuel screw extension. I dont know which one you have but there are press on versions that are very simple and there are 'entire fuel screws' that are a bit more tricky. If you have the complete fuel screw the hole has to be enlarged to install it - don't try drilling it as you can crack your float bowl easily (it can be done though). I would use a dremel on it - and make sure you get all the tiny bits out too.

 

[MCassle]

I purchased the press on type of fuel screw extension; I think it was $18. I didn't know about a permanent one, but I don't feel up to drilling on my new bike anyway ;)

I just want to ride the dang thing already ...

Matt

 

[mrmodine]

Actually, the one CZ sold you won't fall off either...it will stay on for you.

 

[TooBadBrad]

IMO, most are making the jetting too hard. Just raise the stock needle 2 clips, turn fuel screw 1 1/2 turns out. That's how mine was delivered from enduro enginering, and it runs great with no flat spots, no blue pipes, no overheating and a comfortable 55 miles before reserve.

 

[placelast]

Originally posted by TooBadBrad
IMO, most are making the jetting too hard. Just raise the stock needle 2 clips, turn fuel screw 1 1/2 turns out. That's how mine was delivered from enduro enginering, and it runs great with no flat spots, no blue pipes, no overheating and a comfortable 55 miles before reserve.

On an assumption TBB's is a G model, then let's do it tomorrow at noon, Matt! You can do your maiden voyage early Friday afternoon...

 

[TooBadBrad]

Yes, mine is a G model

 

[MCassle]

Originally posted by placelast


On an assumption TBB's is a G model, then let's do it tomorrow at noon, Matt! You can do your maiden voyage early Friday afternoon...

Would love to, but have two problems. One is getting the whole day off Friday (wife is starting to give me grief), the other is running that new bike in Clear Creek with no skid plate (or any guards for that matter). Still waiting on parts.

I'm sure I can do the needle, it's the main & pilot that I've never done. I'll still take you up on your offer after I get the bike armored up. I think running a bike without a skid plate would be taking a huge risk, especially with some of the rocks that call CC home ;)

Matt

 

[OldStroker]

I have the EMN needles and will install them, along with doing the BK mod. OldStroker@sbcglobal.net

 

[E-Ticket]

The '03 KTMs use a different carb than the 00-02's. You do NOT have to drill out the float bowl for the extended/replacement fuel screw.

I put the Kouba Extended fuel screw on mine and have been very happy. Installation was a snap. When you have your carb tilted sideways to change your main jet, simply note the number of turns on your Fuel Screw (counting turns out from *gently* bottomed), and screw out the stock fuel screw.

If replacing the stock with the extended fuel screw - simply transfer the small spring, washer, and o-ring (keep in the same order... make sure you get all three items transferred) to the new fuel screw and re-insert. Screw back out to original setting and you're done.

One caution: if you are turning more than 2 1/2 turns out (stock or otherwise) - you probably need to go up one Pilot Jet size. If you screw the Fuel Screw out too far, you run the risk of it being too loose and vibration causing it to back off and fall out. This is true for both the stock or aftermarket fuel screws.

Currently, I am real happy with the following settings on my '03 KTM 450 EXC:
-- Kouba ext. fuel screw - 1 3/4 turns out
-- stock Pilot Jet (*may* go up one step with more testing)
-- 165 Main Jet
-- OECEMN needle on 4th clip position (counting down from top)
-- BK Mod set at ~ 1 sec. of squirt duration.

With stock jetting: hard to start, ran like crap, blued the pipes in 10 seconds. Now? Runs great, no bog, will pull the front end up at 39rpm by just snapping the throttle. Have no idea on gas mileage with these settings - not enough good weather yet! <boo-hoo>

Good luck! -- E-Ticket

 

[MCassle]

Thanx for all the suggestions guys ... In my haste to order parts, I neglected to get a main smaller than a 168, so that's the one I went with. Left the pilot stock at 42, changed needle to OCEMN at 4th clip from top ... whoa, what a difference. Could only ride a couple of miles around the neighborhood (I'm right in the middle of the city) w/o tickin' off the yuppies, but can tell that this bike runs 100% better. Still a little bit of backfire on deceleration, but nothing like it was.

I've heard of the 'BK mod', but would like to here from any other 450EXC owners who have done this (yea? nay?) before I embark on such a project. I'm thinking on my maiden ride next week, I will play with the fuel screw to hone the jetting in.

Thanx again,
Matt

 

[geremacheks]

TooBadBrad's advice should work.

I got a little different info from Enduro Engineering for my 03 525. They told me to lift the stock needle all the way up, and turn out the fuel screw about 2 1/2 turns. That's what they do to their showroom bikes.

I'm now in the 5th clip from the top with stock needle, pilot from 42 stock to 45, stock main jet of 178, and fuel screw out 2 1/2 to 2 3/4 turns.

No more lean running. Runs near perfect. Pretty simple.

Access needle from top of carb. The pilot (and the main) can be reached from the carb bowl drain nut----simple, again. This, with the seat and tank off the bike, the carb twisted out (the bowl) toward the kickstand. (My 200 wasn't this easy.) ;)

 

[MCassle]

Just a quick note on my maiden voyage ... after 2 hours on the KTM, and only doing fireroads for the initial break-in, my fuel screw fell out!! I had it at 1.75 turns out (so I thought), and had a press on knob installed on it.

Next time around I will leave the little aluminum knob off of it. It weighs next to nothing, not sure if that had something to do with it.

I may go to a 45 pilot in an effort to keep the fuel screw at something close to stock settings (1.25 turns out)

This happen to anyone else or do I just have bad karma? ;)

Matt

 

[MrLuckey]

I have heard of that happening to someone else. I am planning to put a zip tie or maybe safety wire mine to something close by. At least this way if it falls out it will hopefully still be attached to the bike.

 

[geremacheks]

So far, no need for quick access to the fuel screw. I'll try to keep mine stock, without any additions. Shouldn't be falling out then. :thumb: