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Beta xtrainer jetting

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Going to pick ours next week... anyone have any winning combos for 5000 to 10000 or somewhere in the middle?

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No but I am 1300 to 6000 feet ride wise,

we will all just post what we come up with.

It looks like you can get a jd jetting kit also called Lectron and they have already sent a few to Europe with great results...

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It looks like you can get a jd jetting kit also called Lectron and they have already sent a few to Europe with great results...

 

I'm off from knee work for a while,

nothing better then a brand new bike you cannot ride.

 

I actually look forward to peoples post on jetting and needles.

After years of YZ 250 ownership I went from a kit person to a 

2 slides, 3 needles and a two handful of jets guy.

 

While I am sure I am no where near many of you but I hope to

eventually understand this Beta enough for summer and winter

in my 4700 foot spread. 

Edited by baby arm holding apple
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I'm off from knee work for a while,

nothing better then a brand new bike you cannot ride.

I actually look forward to peoples post on jetting and needles.

After years of YZ 250 ownership I went from a kit person to a

2 slides, 3 needles and a two handful of jets guy.

While I am sure I am no where near many of you but I hope to

eventually understand this Beta enough for summer and winter

in my 4700 foot spread.

I don't know I tell you I am too poop lazy for that:)

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I haven't gotten a chance for extended testing yet and it's snowing today.  However, when I got the bike, I ran it as was and found the mid throttle was a little bit on the rich side. There are two needles came with my bike, NOZJ and N1EJ.  The NOZJ is a half clip leaner, so I went with it and the jetting at around 5500 is good.  I'll take it to 8000 ft area and check the jetting again later.  My carb setup right now is PJ 35, MJ 155, NOZJ at 2nd clip and AS is 2-1/4 turn out.  Temp was in the low 70's. My guess is that for higher elevation, I'll drop the needle or to use 152 main jet and it'll be good.

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I haven't gotten a chance for extended testing yet and it's snowing today.  However, when I got the bike, I ran it as was and found the mid throttle was a little bit on the rich side. There are two needles came with my bike, NOZJ and N1EJ.  The NOZJ is a half clip leaner, so I went with it and the jetting at around 5500 is good.  I'll take it to 8000 ft area and check the jetting again later.  My carb setup right now is PJ 35, MJ 155, NOZJ at 2nd clip and AS is 2-1/4 turn out.  Temp was in the low 70's. My guess is that for higher elevation, I'll drop the needle or to use 152 main jet and it'll be good.

 

Really interested in your findings

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I ended up with a 150 main and will most likley change to the 148 when it warms up... using the red needle on the 2nd clip

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I believe you're using JD kit. I don't know the difference between JD red needle and ZOEJ. All I can do is to figure out oem needle jetting.

Correct just throwing it out... I can tell you this... all settings are leaner. .. the clip height was the same as stock but main was leaner from 155 to 150... I though it ran well at stock even at 5000 and above but the jd kit really made it much crisper and more responsive.

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I believe that there are going to be quite a few 4t riders coming to the XT, and 2t jetting is different enough to warrant some relearning. For what it's worth, I found this on advrider:

 

***2 STROKE JETTING and TUNING:***

 

The following applies SPECIFICALLY to jetting a 2 stroke. 
If you want to jet a 4 stroke I would strongly advise the detailed guide that was made quite some time ago by Mikuni for it's pumper carbs (I followed this guide for jetting my Mikuni TM40 on my XR650R).
That being said...

The very first thing you should do is to check your float level before anything else. But BEFORE you do that, you should make sure that the following checks out:
Make sure:
-You have good compression 
-Your reeds are not worn out
-The muffler packing is good and does not need changing 
-That the air filter is in good condition and not clogged or over-oiled 
-That it has the right spark plug that is clean and has the right gap 
-That it has fresh premix (premix goes bad after 2-3 weeks unless you use a fuel stabilizer like Startron, etc.)
-That the carb is clean, the jets are tight, that is has no bad o-rings and that the floats, the float needle and the float seat are all good. 
After you know that the above is in order and is fine, you need to make sure your float level is correct. If this is off, it will affect the bike badly. Unless your manual states otherwise, you check this by holding the carb upside down and making sure the float needle is seated. Then you slowly tilt the carb at an angle until the float tang just separates from the needle. Tilt it back slowly till it just barely touches - and this is when you take your measurement. The carb could be anywhere from like 45 - 60 degrees or so (more or less) when at this position to check it. I just cut a strip of thin cardboard (from packaging or something) at the height I want to set it to and I adjust the tang accordingly. 
Since this thread applies to the KTM 300, I have to say that at the least for the earlier models, that the float height is generally (and often) raised 1 or 2mm higher from what the manual states. In my case I set it to 18mm. At the recommended 16mm, the actual float level (of the gas) was simply too high and felt like it was drowning out the bike and gas would spill out of the carb at slight angles - even though the needle and seat are perfectly fine. 
Once you are certain that everything stated above is fine and that the float level is correct, then you can do the following to ascertain where you need to go with your jetting.

First off, to make tuning alot easier, put a piece of tape on the throttle housing - like masking tape or aluminum tape - and draw a bold line with a permanent marker. Then, if you have anything but black handgrips, draw a bold line on the rubber closest to the housing at 0 throttle, at full throttle, and then split the difference and mark it at half throttle and then subsequently at 1/4 and 3/4 throttle. You should have 5 bold reference lines or large dots on the large rubber ring on the right handgrip that can be quickly looked at when riding. If you have black handgrips, you can try whiteout or see if you can make some masking or aluminum tape stick to it. These markings will greatly help with the following jetting procedures.

PILOT JET/MIXTURE SCREW:
If you can start it cold with no choke, the pilot circuit is too rich.
If, when warm, the idle seems to hang when blipping the throttle, the pilot circuit is too lean.
The best way to set a pilot circuit is with an RPM gauge. Warm the bike up and turn the mixture screw to where you get the highest RPM. If it's below 3/4 turns, or above 2.5 turns, change the pilot jet and try again - generally if you're past 2.5 turns then you need to go to a smaller pilot. If you're at less than 3/4 of a turn, then you need to go bigger.
When riding it (after it's been fully warmed up (but not heatsoaked of course) - you should be able to ride in 3rd gear, with the throttle BARELY cracked open, and it should cruise smoothly. If it sputters and crackles, the pilot is too rich. If it bogs, the pilot is too lean.
More tuning info regarding the Air Screw:
With a hot engine while on the stand, turn the a/s out by 1/4 turn at a time until you notice a hesitation the moment you whack the throttle. Allow about 15 seconds between throttle whacks. Then turn in by 1/8 turn until there is no hesitation. Take note of how many turns out the a/s is from seated.
1.5 out is a good place to start. 
If no hesitation at 1.5 out, then continue going out until there is some hesitation. take note of how many turns out the a/s is. If there is some hesitation at 1.5 out, then go richer by 1/8 turn at a time, wait about 15 seconds between tests. Note how many turns out a/s is when hesitation stops. The hesitation will be the moment you snap the throttle open from idle. You really only need to snap open from idle to about 1/2 throttle for the test.
Again, if you find the end result to be at more than 2.5 turns out or 3/4 turn in or less, change your pilot jet accordingly.

NEEDLE CLIP:
Riding in 3rd gear, with a warm engine and the throttle BARELY cracked open, roll the throttle to 1/2. If the bike sputters and crackles, and you feel like you have to keep rolling on the throttle to smooth it out, the needle is too rich. If, on the other hand, you get the dreaded 'buhhhhhhwaaaaa', the needle is too lean.

MAIN JET:
Riding in 3rd, with the throttle BARELY cracked open and cruising along, whack the throttle wide open. If you end up with a set of handlebars impacting your nose, or you loopout, the main is perfect! If it crackles, smokes, and won't get 'on the pipe' quickly, then the main is too rich. If it gives a 'buuuuhhhhwwaaa' sound and feels like it's sucking for air, then the main is too lean.

ADVANCED TOPICS:
The needle regulates the mixture from around 1/4 - 3/4 throttle. Most people are familiar with the clip position, as it's the most common adjustment, but there's much more to the needle. The jet needle is a long rod that fits into the needle jet. On most carbs, both are replaceable with different sized components. As the throttle is opened, the jet needle is retracted from the needle jet and this creates space between the two for gas to flow through. The more you open the throttle, the more the jet needle is pulled out of the needle jet, and consequently the more gas can pass through the increasing space between them. Below I'll outline the various parts of the jet needle.
Length - The relative length of the needle is adjustable by raising or lowering the clip. If you lower the needle (by raising the clip), then the needle sits deeper in the needle jet. This leans out the mixture across the range of the needle. Conversely, if you raise the needle (by lowering the clip), then the needle is further retracted from the needle jet, and this richens the mixture across the needle's range. Needles are offered in various lengths. If you have a needle which is still too rich, even though it's in clip position 1, then you need to order a longer needle. For example, needle 'A' in clip position 1 is the exact same relative length as needle 'B' in clip position 3. If you had needle A in your bike, and it was still rich - even though you had the clip in position 1, then you could change to needle 'B' and lean things out by going to clip position 2.

Root Diameter - Needles are offered in several different root diameters. The jet needle sits in a hole in the needle jet, as mentioned. The clip position determines how deep it sits in the hole. The root diameter, on the other hand, is the diameter of the needle at it's pointy end. The wider the root diameter, the smaller the space between the needle and the hole in the needle jet. Therefore, a needle with a larger root diameter will be leaner than a needle with a smaller root diameter. The root diameter overlaps with the slide cutaway, which is to say that it affects primarily 1/8th to 1/4 throttle mixture. Typically you would swap for a needle with a larger root diameter to compensate for high altitude (or extreme heat).

Needle taper - Needles taper from top to bottom. As with all principles regarding the needle, the taper is relative to the diameter of the hole in the needle jet. Tapers are rarely changed, but here's a condition which warrants a taper change. Let's say the jetting is perfect at 1/4 throttle, but becomes increasingly leaner as you approach 3/4 throttle. In that case, you would want a needle with a shallower taper. Conversely, if the mixture is great at 1/4 throttle, but getting richer and richer as you approach 3/4 throttle, then the needle taper needs to be steeper. In my experience, needle taper only needs to be changed when the factory mis-spec'd it to begin with. Under very rare circumstances, big modifications to the motor - such as an overbore kit - will require a change in needle taper.
Remember that jetting needs to be adjusted for every 2000' elevation change and every 15 degree temperature change. (Some other sources say every 20 degrees and 2000 - 2500' elevation change - and this is the guideline that I try to follow). If it was jetted right this summer, it's sure to be too lean during the winter. If you rejet it now, when it's cold out, make sure to lean it out a bit in the spring.

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Thanks for the jetting process. From what I can tell, it's better than the full on testing I used to do. I'll give it a try for sure.

One thing I did notice from previous bikes is that with air density change, either elevation, temperature, or barometer, the jetting has a tendency to follow the conditions, to a degree of course.

I've also noticed the temperature affects jetting the most obviously. However, a change of main jet and to adjust a/s are good enough. Take it with a grain of salt as this lazy tuning is not for racing.

Edited by flywheels
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I asked the JD folks when they'll have an X-Trainer Jet Kit.  Here's the answer...

 

From: JDJETTING <jdjetting@comcast.net>

https://www.jdjetting.com

Subject: 2015 Beta X-Trainer 300

Date: May 15, 2015 at 1:02:03 PM EDT
 
We are working on one right now. A week most likely.
 
Thank You
Dave 
JDJetting
1930 Carpenter Rd Se
Lacey Wa , 98503
Phone (360) 350-0557

 

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Funny when I contacted them they told be to order a ktm kit and then included 2 different main jets and then the same needles as the ktm 300

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I received and installed my JDJetting kit yesterday.  It was in a box marked "BETA XTRAINER".  I installed it as per the instructions sheet for my area which is below 1000ft in most areas.  I got to try it out today and I am very pleased with the way the bike performs with the JD kit.  Before the JD kit my bike had a blubber at steady light throttle which I had previously been unable to correct with the needle clip or a needle change to the other needle Beta supplied with the bike. 

With the JD kit the bike runs crisp and clean and the blubber is gone.

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Funny when I contacted them they told be to order a ktm kit and then included 2 different main jets and then the same needles as the ktm 

That's pretty common since they are the same cc. Most motors typically make the best HP with 12-12.5.1 air /fuel ratios. So if you do the calc's to find out the cfm the motor uses you can figure out the jetting required for size and style carb your using. Thats were flow benches make jetting fool proof. Just set the bench @ 8.2" which is about a 12.2-1 air/ fuel ratio and dial the carb in for the cfm at any given rpm. The extra jets JD gives you are for the small % of change due to elevation,bar and temps. For those that hate guessing, Mukini makes a pocket slide rule for jetting adjustments for temp and elevations that might help. http://www.dansmc.com/mikuni_carb_tuner.jpg

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I received and installed my JDJetting kit yesterday.  It was in a box marked "BETA XTRAINER".  I installed it as per the instructions sheet for my area which is below 1000ft in most areas.  I got to try it out today and I am very pleased with the way the bike performs with the JD kit.  Before the JD kit my bike had a blubber at steady light throttle which I had previously been unable to correct with the needle clip or a needle change to the other needle Beta supplied with the bike. 

With the JD kit the bike runs crisp and clean and the blubber is gone.

 

 

From the JD kit description for the Xtrainer...

https://www.jdjetting.com/xcart/product.php?productid=225

 

Accelerator pump modification to improve throttle response 

 

If you don't mind sharing, what is the modification to the AP that they are recommending, or even better, can you scan the install instructions from the kit and post it?

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