Xtrainer jetting - NOZJ Vs. NECJ

[Jake]

Hey guys,

I have a new to me 2017 x trainer and trying to figure out jetting. Done a fair bit of research and after stock first tried a NOZJ clip 2, 155 main, 35 pilot which was okay but still quite a bit of four stroking at 1/8 throttle area.

Now hoping to improve this fitted an NECJ Clip 3, 160 Main and 38 pilot (People seem to suggest stepping up jet sizes with the NECJ?), The 160 main didn't work as was too rich (When flat out it would start to miss and burble, wouldn't clean out). I have now dropped to a 158 and this has improved but think a 155 will work best.
The four stroking is still present and idle doesnt seem as strong, So thinking of dropping back to a 35 pilot. It seems I can improve the four stroking significantly by opening up the air screw on the current set up, but then on the over run with closed throttle i get a bit of bucking and surging. If i then close the air screw enough to eliminate this the four stroking is more noticeable, the adjustment seems to be in the correct range around 1-2 turns. - Im not sure what this indicates at this point but i suspect the step up in jet sizes wasnt needed and its causing the issues.

I plan to now go and fit stock jets (35/155) with the NECJ in clip 3 and see how that feels, Any advice on this is appreciated.
If i can obtain a correct air screw adjustment with the smaller pilot i think it will run nicer. And the top end richness will go with a 155.

Any advice or peoples set ups with NECJ in an x trainer appreciated as im struggling with the conflicting info online.


Im sea level, temps around 60-70F

[njbill]

Have you tried the stock jetting? I am at sea level with a 2018 Xtrainer and the stock jetting is spot-on from 40F to 95F. I can lug the engine in 4th gear and open the throttle without a bog or stutter. It runs like my fuel injected KTM 4t. This is not my first 2t, but it is my first Beta.

[Goatse]

I put an NEDJ in my wife's Xtrainer, didn't touch the stock jets, and it's a touch rich. I think the NECJ would get it perfect.

[Clearvu1]

You might want to take a look at the reeds, could have a chipped edge or a crack. That throws the jetting off and you'll never get it to work right.

[Jake]

Thanks for all the replies.

It had stock jetting when I got it, i was trying to reduce the four stroking/burbling at light loads and low throttle but beginning to think this is just a characteristic of the bike!

I also find at low rpm and more so on the road i get quite a lot of chain slap and a bit of noise around the motor. Possibly the power valve clattering a bit?

Bike only has 20 hours

Thanks