11' 250 race-wa. jetting?

[adv rider]

I ordered the n3cw needle. I plan to try out 40 pilot, 178 main with the stock needle. Hopefully it will work well enough while i get some run time on the engine, hoping to try it out on monday.

I hope it won't be too difficult getting the jetting right, I am not real perceptive of changes/differences unless they are drastic. And i haven't ridden a 2 stroke offroad in 9 yrs- I guess the testing will begin , and i need to make sure i bring spare spark plugs so i am not left stranded.

[Jakobi]

With decent jetting you won't foul a plug mate. I carry 2 spares and in 7500kms on my engine I haven't once needed to swap one out.

If you're playing with the stock needle it has a rather rich end (towards WOT) so it'll happily work with a 175 main. Stock needle should be an N1EF. The difference between this and an N3xx is pretty drastic. Definitely noticable, and all for the better.

[adv rider]

Well I finally got ride, and the jetting seems about perfect I checked the plug 4x just to be sure it wasn't really lean. The plug was new so it will take some time to color. but it definately wasn't to rich. I rode for 1.2hrs and the electrode still had the new look, but not white or gray at all. some black around edge,but not completely.

This was at 40:1 motul 710, about 38-40 degrees.Not sure of elevation probably around 400-500 ft. very wet out, some snow flurries and fresh snow up top.

Had the needle at #3, 40/178. I had a slight hesitation just off idle. kind of like when you turn off choke to soon. so i think i will try 42 plt. or possibly shim needle a half clip position.
But otherwise it ran really good, i could leave the carb alone and be totally happy.

It's hard to say if main jet is ok, as where i ride i rarely get on the main jet. Initially had fuel leakage from overflow, try tapping carb did not stop, so i just rode it and it stopped shortly after. I figure something from tank possibly got in needle seat

Thank you Jakobi !! It would have taken me a long time to get the jetting right

[Jakobi]

No worries. You can either try a half a clip richer needle N3EW#3, shim it up half a clip, or if its just off idle a size up on pilot might cover it. I'd say it will if its cold out. Other option is to step up the diameter one size to an N3CH. Options options.

[adv rider]

Ok, I have been thinking about how my bike ran the other day . I am thinking that going to 42p, and also going to the 180m will be an improvement . Having very little exhaust smoke when running, and being a new engine- wondering if I should have ran a richer mix for the first tank?

Seems like it needs more pilot- it was idling ok , a/s at about 7/8-1 but...that off idle bog. Also since I didn't get much opportunity to open the throttle, and when I did it just didn't impress me much as I was expecting. I figure I can go up to 180 without problem. Also since I will be going to much more wide open event in a few weeks, it will be safer for my engine.

What is a normal amount of exhaust smoke? {motul 710 @ 40:1 } I stopped a few time to look at exhaust-and could not see any noticeable smoke, only smell.
How many miles can I expect out of a tank full , when ridden on the main often? The event I am going to has 30-35 mile laps.
Thanks

[Jakobi]

Don't jet for smoke or spooge. They aren't very good indicators and will vary during a ride depending on how you run the engine.

You won't have done any damage running the bike in with leaner jetting. Don't sweat that! If you have a bog off idle address that first. You're in on the air screw now, so thats the sign. Drop a 42 pilot in and try again. You may find yourself up around a 45 if its cold and depending on your conditions, preferences and fuels.

My bike smokes very little, but will heaps when cold, and will also puff a bit when clearing out if I've lugged it around. I only ever get an oily ring around the exhuast tip, but get loads of spooge drip from the header when the o-rings blow, and a steady flow from the PV vent.

[adv rider]

Took my second ride today. Jetting 42p, 180m, N3CW-#3. The temp today was about 30 deg warmer than the 1st time, so it's hard to compare that part.

I noticed first off that it smoked a lot more on warmup, and I needed to clear it out to ride it. But after that initial clean out it didn't need that again. I wasn't able to notice a diff with the airscrew settings, so I just left it at 1.5. I did have to turn out my idle screw to bring the idle down to reasonable, now it will idle about 30 sec the stall. That's about how I like it.

Felt good on the trail, good up top too. It didn't load up at all during the ride.So I think it was good stepping up the jetting. After I was done riding I looked at plug, it still looked pretty clean. I was surpised that 2.5 hrs of riding didn't color it. The threads were black , but the electrode still had a new raw metal look to it, but not like it was lean.

I am just going to leave it as is for the coming 100 mi event, and see how it does.

[TeamJames]

Can anyone help with PWK needle part #, the genuine Yamaha needle (N3CW) or 4SR-14916-CW-00 here in Oz retails for over $40, we have a Keihin dealer here but he can reference OME part numbers, is a CCK needle the same as a N3CW ?

[Jakobi]

James. The N3CW is OEM for Yamaha and KTM. Either dealer will help you out. KTM is cheaper than Yamaha here. Go figure. You can order them in from the states for around $10 + postage. Usually a few days back order. Or around $25 locally through ktm. About 3 weeks back order.

Where are you located?? I might have a spare. I'll sell it to you for $30! Hahaha!

[desertgasser300]

Crap, I ordered the wrong needle. I ordered an N3CK.