yes hanging

 

I think it was where i was used to my 350! Put 14 now and Im used to it now.

What way would I need to turn the air screw if Im getting a bit of over run? currently at 1 1/2

 

'over run' .... do you mean hanging? try it on one turn out (screw in fully clockwise then out anti clockwise one full turn; dont screw it in mega tight by the way) if it still does it at one turn, then you will need to dump the 38 pilot jet and put a 40 in there.

 

It's cos your gearing is too low, try the 14 tooth sprocket Iv'e just tried 13-49 on mine and it was too revvy and abrupt. Also has the grey wire been disconnected under the tank? Some say this doesn't make a difference but it certainly did on my 250xc, changes the ignition map between trail and mx.

 

Hi as below put a 14 tooth on may be a 40 pilot and wind the green spring in a few turns .

 

I found my TE300 fine with the same jetting but it had a standard pipe fitted

 

Thanks Al, had a feeling the Gnarly could be causing the hit, I prefer more mellow as i do tricky technical stuff.

Anyone fancy a swap?

 

Also, I don't like to tell anyone but I use a throttle cam too... makes a massive difference to the roll on. Makes it like a 4 stroke.

It is cheating but I'm sticking with it because a 300 is like cheating anyway.

 

Yes need to recalibrate my throttle hand!

 

screwed it in 3 threads, maybe im used to the sluggish 350 i had as a stop gap

 

Turn it back until you see two threads, makes the transition mellower. The further you turn it in the harder the hit...

 

Mh...you're probably insensitive, there is a noticeable difference. Did you check how many threads are showing on the PV screw?

 

And check which PV aux spring you have installed. The red one may be too aggressive for you...

 

I gone from yellow to green but cant notice much difference

 

Ok I have a 14T will give it ago

 

I have just got a 2015 exc 300 with NECJ needle, 170 Main, and 38 Pilot, the bike came with a FMF gnarly fitted, green PV spring, 13-51 sprockets.

Previously I had a Husqvarna 2015 TE300 with exactly the same carb setup though 168 main jet & standard Exhaust, and this was much more tame/tractor like in the low revs which I liked better.

Love the KTM but the only thing Im finding is the power is aggressive low down/early in the revs, and making me loose traction easy, what can I change?

 

I had a gnarly on mine and it makes a big difference to the both bottom and top. Very strong off the bottom and pretty flat up top. Changed back to standard pipe and it is waaaaay nicer to ride now. Plenty of grunt without the gnarly.

And check which PV aux spring you have installed. The red one may be too aggressive for you...

Not off the bottom it won't.

 

I have been using a 168 main,n2zj needle in 3 slot and 38 pilot jet for everything above zero.Now in the winter i richened it up to 170,40 pilot and lifted the needle to 4 slot,also changed to pure alkylate fuel which seems to run a bit richer than before(premium 5% ethanol).

 

I set my air screw going by the advice of the slavens youtube. Basically wind it out just to the point when a snap wide open throttle from idle doesn't cause a bog. I must admit I haven't changed it since the summer so that's probably why!

 

its amazing how different these bikes can be - since that first post I have fitty a fatty and a powercore and went to 40 p.j and 168 m.j, but have stuck with NECJ at clip 3 ..... I am using 40:1 premix - as it leaves a good residue on the crank with no spooge on the pipe - so that could suggest that my jetting would be too [fuel] rich for someone using 60:1 (50:1 is ok, but too [fuel] rich in the summer)

 

I am sure it would get enough oil with 60:1 otherwise KTM would not recommend it. Concerning the spooge I think that the pilot jet and airscrew setting have much more influence than the mixture itself. It may sound weird but I made an error when mixing fuel (50:1 instead of 60:1) and didnt realize any difference at all. I found out in the evening when I refilled my little oil bottle which I have in my backpack when I am out in the Romanian wilderness.

 

The detonation was happening at high road speed, 60mph and faster when going down slight hills, or easing off to slow down slightly, and was in the 1/16 - 1/8 throttle region. This is where the pilot jet, air screw, straight section of the needle (nec'J'), and position of the beginning of the taper have most effect (clip) The main jet has virtually no effect at this small throttle opening.
In the summer, all fine no detonation due to a leaner mixture required, but in sub zero temperatures, it's too lean, although running super 4 stroke smooth!
There are 4 main ways to richen up this region.
Lower the clip position, (raise needle)
Decrease needle diameter, ie go from NECJ to NECW
Increase PJ
Wind in AS

So I raised the needle 1 clip, didn't need to change the PJ, as I had loads of richer adjustment left on the AS, and wound in the AS 1/2 a turn which was too rich, so then backed off 1/4 of a turn to get it bang on. I have found the AS is the adjustment that has by far the most difference in rideability and clean running.

sizzler's original question is how to clean up his spluttery bike, so just a matter of reversing the process.

Also worth noting, that if the bike won't clean up by a bit of AS tweaking and maybe dropping a PJ size, there may be something else wrong like broken, bent, worn reed petals, or a crank seal leaking etc..

It is amazing how sensitive these high performance 2 strokes are to jetting. To get them running really nice, they are on a knife edge, a tiny tweak here and there makes a huge difference, and weather and altitude too.

 

The detonation was happening at high road speed, 60mph and faster when going down slight hills, or easing off to slow down slightly, and was in the 1/16 - 1/8 throttle region.

Same with mine, except that it was much warmer. I started with a too lean jetting as I thought I can just use the same set up as on my 2015, but that was a big mistake. It was running way better than with the Mikuni though.

This is where the pilot jet, air screw, straight section of the needle (nec'J'), and position of the beginning of the taper have most effect (clip) The main jet has virtually no effect at this small throttle opening.

That's what I have learned now.

There are 4 main ways to richen up this region.
Lower the clip position, (raise needle)
Decrease needle diameter, ie go from NECJ to NECW
Increase PJ
Wind in AS

I did #1 and #4 plus bigger main jet, but didnt know what finally cured it. Thanks to your post I know it was most likey the AS plus the lower clip position.

I have found the AS is the adjustment that has by far the most difference in rideability and clean running.

Its influence is much bigger than I expected. Since I try it 1/4 turn wise and ride it after every 1/4 turn to compare I get it better and better. The difference between spooge and no spooge was just a 1/4 turn.

It is amazing how sensitive these high performance 2 strokes are to jetting. To get them running really nice, they are on a knife edge, a tiny tweak here and there makes a huge difference, and weather and altitude too.

100% true.

 

NECJ needle at clip #3
165 main
38 idle
AS 1.5 out
Green spring
Adjuster 2 casing threads showing
Softer ignition map setting

Any tips for low speed (2/3rd gear) steady state throttle? Pulls fine when accelerating but when trying to maintain a slow speed like through a twisty wood track it tends to splutter a bit or wants to be accelerating. Would a 40 idle jet help?

 

It's spluttering because it is rich. Try air screw at 1.75, 2, 2.25 and 2.5 turns out and test ride each time. If it's still spluttery at 2.5 turns, stick in a 35 PJ and start the AS at 1.5 turns, the gradually wind it out again as before. You could also try the needle on clip 2, but it might be a bit too lean and boggy in this very cold weather
I've just put my NECJ back to clip 3 winter setting, as clip 2 was too lean, and it was detonating on low throttle high revs. I always have a 35 PJ, and tend to run the AS at 2.5 turns in winter. As it was seriously cold on Saturday, there was still a tiny bit of detonating, so I tried 2 turns out, but it was too spluttery on technical lanes, so 2.25 turns and bingo - sweet spot! No detonation, and no spluttering.

 

I use what ever manual says it should have on that temperature. If it still feels a bit rich then one level smaller on idle. Check you manual, it will help out.


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Yeah - 165 with 50:1 will be fine.

 

I'm running 50-1 I think I might go to a 165 and see how it rides and order a 168 as well

 

always a 165 till I changed the piston - to a no. 2 - then it needed a 168 to keep good at wot. I would say that 162 is a bit lean (although probably ok on 60:1 ..... )

 

What main jets do most of you guys run. My berg 300 has a 162 main is that a bit lean ? Once I had detonation going wide open throttle from 3rd by the time I got in to 5th it went odd it started surging then the detonation noise started. Pulled over checked fuel and I was a inch above the pickup in the tank went back out and all was fine I put it down to crap in the carb but removed the bowl today and it was clean

 

What main jets do most of you guys run. My berg 300 has a 162 main is that a bit lean ?

I run a 162 on my 300 and its fine, but I use a JD needle. If you use the OEM needle it might be a bit lean and you could try a 165. What mixture should you use? 50:1 or 60:1 ?

 

cheers.

 

So all the posts on this thread ... is this the same for the TE300 husky (the same engine right) ?

 

yes. tried and tested.

 

in a not running weak kind of way .... hanging onto revs when you come to a stop / blip .... the 38 was fine on my bike when it was on low hours, but by 50 odd hours it needed the 40. All the other jetting is as per page 1 of this thread.