Rod

Member
Nov 26, 2001
8
0
Tonight I swapped out my miserable OBDVR needle (CA 520 EXC) for the OCEMN, and installed a 165 main and a 50 pilot.

However, can anyone tell me about the following:

Imagine taking the bowl of the carb off. On one side, pointing up towards the top of the bike, there is a rubber boot/diaphragm about 1/2" long, from which protrudes a rod about .1" in diameter, bent at a 90° angle.

Does the bent portion of that little rod insert into something when you re-assemble the bowl?

I didn't take notice (famous last words) when I pulled the bowl off. I assume it has to do with the accelerator pump, in my limited but growing understanding of FCR carbs.

Also, what is the (jet?) opposite the pilot jet? Aligned in a row are the pilot jet, the main jet, and another jet, which I mistakenly pulled first when attempting to change the pilot. Obviously it was not - it was marked as an 85.

Thanks for any assistance.

Rod
 

brillmtb

Member
Dec 12, 2001
16
0
I also had my 520 2002 EX/C Green bike converted back but only recieved one long needle jet looking like thing from the dealer. Is there a second part that needs to be replaced.

The reason I ask is that it seems my bike is running a little leaner than the same bike that my brother in law bought which was a non green stickered bike.
 

Rod

Member
Nov 26, 2001
8
0
Ok, got it sorted.

Brill - you need to replace the needle and the main jet, and possibly the pilot jet. If you look at my post above, it basically describes what you need to do.

However there are many possible variations on the theme. If the needle your dealer gave you says OBDTM around the upper circumferencet, you can replace the one in your carb with that one and you will alleviate the over-lean condition. However people with a lot more experience than I are suggesting the OCEMN needle, which is what I used.
 

brillmtb

Member
Dec 12, 2001
16
0
Alright, how about some more input here. What is the best setting for the 2002 520 Ex/c? I bought a green sticker bike, they told me they returned it to stock, what ever that is, but I only recieved a single needle in my package that they handed me.
 

cbm4stroke

Member
Feb 29, 2000
24
0
Stock Jetting for the non "G" models.

Needle OBDTM clip #3 from the top

Pilot Jet #48

Main Jet # 175

fuel Screw + 1.5 turns out from seated.

Some of the "G" models came with 45 pilots and some came with 48 so you need to look and verify.

Alternate needles are OCEMN, available from Carb Parts Warehouse or Sudco, OBELN available from Yamaha. I run the ELN #3 a 48 pilot, fuel screw at 3 turns out and a 165 main jet, 02 520 exc. The needles which start with a "E" (eg ELN, EMN) have a steeper taper and come onto the main jet faster and will run too rich on top with the stock 175 main jet. The ELN needle is the stock needle in the Yamaha 250F and it is a 1/2 clip position richer than the EMN needle.

The difference between a OC and a OB needles is the material the needle is made of. The OC needles are brass and the OB needles are a alloy. The alloy needles are OEM, more expensive and wear better as they have a harder exterior.


Clark
 

Unit74

Member
Dec 16, 2001
494
0
Originally posted by cbm4stroke
Stock Jetting for the non "G" models.

I run the ELN #3 a 48 pilot, fuel screw at 3 turns out and a 165 main jet, 02 520 exc.

Clark

You really should move up to a 50 or 52 on the pilot. If you are going more than 2 turns out, a new jet should be fitted.
 

brillmtb

Member
Dec 12, 2001
16
0
I greatly appretiate the advice and info on this site.

Thanks

Can you tell what jets, etc you have by markings on the outside or to I have to take everything apart?
 

Unit74

Member
Dec 16, 2001
494
0
Slip off the crank case vent hose, remove the thin black hose on the bottom of the bowl, loosen the clamp on the rubber boot which connects the carb to the cylinder. Only loosen the clamp which is on the carb side(theres 2 clamps), loosen the clamp on the airbox side. Carefully twist the carb sideways so that the bowl will become exposed on the sprocket side of the bike. You will need to remove the allen bolts and then slowly work the bowl off. The AP rod will slide right out and stay connected to the actuation arm above the carb. You should see the main as well as the pilot jet. You might need a flashlight but non the less they will be in view.

As far as the needle goes. My delaer got on the hook with the KTM distributor in El Cajon, Ca (Just down the freeway) And he said they have been reading the boards to come up with jetting for the 03' models and the best combo they have so far is a an OBDTM in the 7th position(stock is 6th) a 48 pilot, 1.5 turns out on the screw. That's it. This was for the 400 EXC but it should be very similar for the 520 as well. The test bike was an 02 model.
 

brillmtb

Member
Dec 12, 2001
16
0
My limited understanding is that the OBDTM is the Green Sticker bike and it runs horrible. I live in OR and want to go back to ideal settings. I have read a couple of recommendations that suggest the following

OCEMN, 165, 50, 2 turns out

How does eveyone else feel about this recommendation over the Green sticker OBDTM, 175, 48, 1.5 turns out OR the post just before this one.
 

OLD STROKER

Member
Feb 19, 2001
89
0
The needle on the Ca. only bikes "G" model is a DVR .
The DTM comes in the 49 state bikes and should come in the little tool bag you get when you buy your "G" model.
 

Unit74

Member
Dec 16, 2001
494
0
OLD STROKER

One of the guys i have ridden with in the past rides with the west coast distributor and those needles will not come with the G model. At first they did, but KTM got some heat from the EPA so they are removing them from the kits as they are imported. I have been trying to get a DTM for a couple of days now with only one bite to speek of. My dealer could not get the DTM either as ktm is holding on to them according to him. Again, he is rying to get the dist. to give him a few for his peeps but no luck as of yet.
 

cbm4stroke

Member
Feb 29, 2000
24
0
UNIT 74

Concur with 50 pilot.

I did not have a 50 pilot an would go to it for evaluation if I had one. I Forgot to mention that I'm running a ProCircuit T4 slip on. It does require slighly richer jetting down low. I have extensively run the Stock and T4 back to back and there is no question the T4 pumps out better low end and mid range. It really snaps. I feel on top its a push between stock and T4. The T4 is too loud for the forest but OK as far as I'm concerned in the desert. Even with the T4 the 520Exc is not as loud as my WR400 was with the baffel removed.

Clark
 
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