Factory Needle/Jet Setting EC250
 

Hi,

I have just got myself a 2005 EC250 and this is how it was set up by the previous owner

Needle N1EF clip pos #5
Main Jet #180
Pilot #38
Air Screw 3

FMF Gnarly Pipe

With this set up it was running very rich and had a massive problem in the mid range, it was like the engine was 'missing' but top end was brutal
It also leaked fuel from the carby out the overflow when idling on the side stand

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So I have decided to run the factory settings

Needle N1EC clip #3
Main Jet 185
Pilot 38
Air Screw 2.5

Fuel/Oil 50:1

I have just put a new fuel intake Valve in the carby and checked the float height.
It also has a new crankcase oil seal.

Obviously I have never run the the 'stock' settings, can anyone tell me how the bike should run with factory jetting setup?

Thanks
Tim
South Australia

Looks like way over the top rich to me.Go back to original setting and drop the needle one clip at a time till it runs right.If still not right go to n1eg needle or suzy nedw.JD blue works good too.Heaps of info in this forum on this,ala jackobi.

As for the float height:
Is is still leaking on the side stand? If the needle valve replacement didn't solve the problem, you will have to adjust the float height a little.
It seems the new and old carb versions can benefit from a slight lowering of the fuel level. Just a mm or 2 at most.

If you do a search on the float level you will find heaps of info. When it comes to standard jetting they are thirsty and way rich!! Depending on what sort of power delivery your after will determine what needle you use. Search that aswell and you will get loads of info. You will also need to tell us where you are what elevation,temps etc

Clip 5 is towards the pointy end of the needle and clip 1 at the top. At clip 5 it would be so rich the bike would be flat out running. Without knowing too much about the 2005 models, I can tell you the newer ones benefit from leaner jetting. As suggested start at the bottom end work your way up.

1. Float level. http://www.gasgasrider.org/forum/showthread.php?t=11886 (This has been stickied) Note: that this is for the newer carbs but same basic principals. I think the float level on the original PWK was 16mm.

2. Needle Diameter and Pilot Jet. Needle in middle clip. Idle screw backed out so the slide is only a few mm up. Air screw at 1.5 turns and then change pilot jets until you get one that allows the bike to idle. I'd suggest starting with a W/I diameter needle. Maybe a 48/46 pilot but you may find you can come down as low as 40.

3. Needle choices. N1EI/NOZI (GG/TM. Rich off the bottom.) NEDW/NECW (Suzi needle. Smooth transition) N3EW/N3CW (Yamaha. hard transition). There are threads to read if you use the search. Start in clip 3 and change it as required.

4. Main jet. The size will vary depending on the needle and profile taper you choose. Start rich and work down as required, checking with plug chops.

In relation to what you have changed, if you went from clip 5 to 3 you have leaned the needle position. You have however gone 2 sizes richer on the needle diameter which will make the richness off idle worse. You've also gone richer on the main. Ideally you want to follow a strategy as I've posted above where you set a starting point and work on each circuit independantly until you are happy and then move on to the next. If you change all 3 at once you won't be able to know exactly what each change makes and will just be stabbing in the dark.

Thanks for all the info, the needle clip was actually in postion 1 at the top. not postion 5 like I said (sorry)

Float is spot on at 16mm

South Australia
Elevation 0-1000ft
temps at this time of year 10'C to 18'C (50'F to 65'F) these are averages

Take a look at this thread, should let you know what others have ran.

http://www.gasgasrider.org/forum/showthread.php?t=3800

In my 300 I personally found the same with the stock needles. Really rich off the bottom and would rip up top. Would load up and smoke like a chimney if I wasn't hard on the throttle all the time. Ie 2 minutes of ST and it was chuggin. I needed the idle screw right in to make it idle and even then it only just did at full temp.

I'd suggest grabbing a handful of jets and a couple needles and playing to see what works best. My suggestions for starting are a NEDW and a N3EW. 40-45 pilots. 172-180 mains. I've purchased through http://www.powersportsplus.com/ before and although it often takes a week or two for them to arrive and some needles are on back order, its just as quick as trying to get them locally and a fair bit cheaper.

work your main done a size at a time till it revs out clean. then bump your pilot up a size or 2. i'm betting you'll end up somewhere around here:

175, #3, 42 pilot, 1.5 a/s


180/185 seems realy rich, but jetting is totally machine dependent...