KTM 250 SX 2018

AJ565
Profile picture for user AJ565
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2110
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San Antonio, TX US
AJ565 6/30/2019 1:55pm
6/30/2019 1:55pm
r18b wrote:
40.4 with the original pipe? 44.4 with a hgs?? Torq 38.1 and 40.1? Or do i see it wrong? If i remember right some one here...
40.4 with the original pipe? 44.4 with a hgs?? Torq 38.1 and 40.1?

Or do i see it wrong?

If i remember right some one here was saying his 250sx was pulling 51hp with a pc pipe and some vp fuel. Now i see this i wonder how much difference there is in a dyno or that he was sucking his big thump to get those nummers.
AJ565 wrote:
Your jetting is to rich causing the low numbers. Stock pipe MXA had 47hp and with a PC pipe and silencer 49hp on a chassis dyno...
Your jetting is to rich causing the low numbers. Stock pipe MXA had 47hp and with a PC pipe and silencer 49hp on a chassis dyno. My bike with a rejet, PC setup, and u4.4 made almost 51hp.
mx4all wrote:
U think so? Looking at the sparkplug the bike doesn't seem that overly rich?
Ignore what the plug looks like. Unless you did a plug chop and then cut the plug to measure the base it’s useless.

Try this jetting, I’ve had nothing but positive feed back from everyone that’s tried it.

With C12.
MJ 460
PJ 32.5
AS 2.0 turns out
NJ S-4 (ktm part)
Needle 42-75 3rd clip (I got mine from Yamaha)
Slide 5.75 (2004 KX125 option part)
PV 1.75 turns in stock spring
Straight C12 mixed 60:1 with amsoil dominator
AJ565
Profile picture for user AJ565
Posts
2110
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Location
San Antonio, TX US
AJ565 6/30/2019 1:58pm
6/30/2019 1:58pm Edited Date/Time 6/30/2019 2:12pm
mx4all wrote:
What's up everyone What weight and spring rates do you guys have? The numbers in the manual is with gear on, right? I weight 196 and...
What's up everyone

What weight and spring rates do you guys have?
The numbers in the manual is with gear on, right?

I weight 196 and I got a 4.8nm spring and I get 35mm sag and 105mm race sag.

I have a Trax shock (turned off) and run a 4.5 spring. I’m 175lb and that’s what PowerBand put on it when I had the shock valved for me. It’s valved stiffer though MX A/fast B settings.
opyguy
Profile picture for user opyguy
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571
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8/22/2016
Location
Boston, MA US
opyguy 6/30/2019 2:05pm
6/30/2019 2:05pm
AJ565 wrote:
Your jetting is to rich causing the low numbers. Stock pipe MXA had 47hp and with a PC pipe and silencer 49hp on a chassis dyno...
Your jetting is to rich causing the low numbers. Stock pipe MXA had 47hp and with a PC pipe and silencer 49hp on a chassis dyno. My bike with a rejet, PC setup, and u4.4 made almost 51hp.
mx4all wrote:
U think so? Looking at the sparkplug the bike doesn't seem that overly rich?
AJ565 wrote:
Ignore what the plug looks like. Unless you did a plug chop and then cut the plug to measure the base it’s useless. Try this jetting...
Ignore what the plug looks like. Unless you did a plug chop and then cut the plug to measure the base it’s useless.

Try this jetting, I’ve had nothing but positive feed back from everyone that’s tried it.

With C12.
MJ 460
PJ 32.5
AS 2.0 turns out
NJ S-4 (ktm part)
Needle 42-75 3rd clip (I got mine from Yamaha)
Slide 5.75 (2004 KX125 option part)
PV 1.75 turns in stock spring
Straight C12 mixed 60:1 with amsoil dominator
aj,
Is the S4 richer than the stock S1?
I am really struggling w/a lean hanging idle, 37.5 pilot, 450 main and richest needle (42-71) on the richest clip (5th down)....could definitely be richer, thinking richer jet needle would get me there
thanks
AJ565
Profile picture for user AJ565
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2110
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Location
San Antonio, TX US
AJ565 6/30/2019 2:05pm
6/30/2019 2:05pm
lukemoto wrote:
[img]https://p.vitalmx.com/photos/forums/2019/06/30/357326/s1200_20190629_092549.jpg[/img] Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax...

Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax but the cool factor helped me decide to try it.
I have one and it’s setup with the trax system off. IMO it’s a noticeable step up from a stock shock, but I feel a revalve with a bladder conversion is almost on the same level and more affordable for most. As in I don’t think most would notice any difference between the two it’s that close. The stock shock works really well on these bikes once it’s setup for the rider. I think the best suspension improvement to my bike was the ride engineering performance link out back and the cone valves.

The Shop

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AJ565
Profile picture for user AJ565
Posts
2110
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3/12/2012
Location
San Antonio, TX US
AJ565 6/30/2019 2:08pm
6/30/2019 2:08pm
opyguy wrote:
aj, Is the S4 richer than the stock S1? I am really struggling w/a lean hanging idle, 37.5 pilot, 450 main and richest needle (42-71) on...
aj,
Is the S4 richer than the stock S1?
I am really struggling w/a lean hanging idle, 37.5 pilot, 450 main and richest needle (42-71) on the richest clip (5th down)....could definitely be richer, thinking richer jet needle would get me there
thanks
Yes it is, but you’ll need the slide, and needle to go with it since they all work together. Give the jetting I posted a try and you’ll have a crisp bottom end that pulls hard and no hanging idle.
AJ565
Profile picture for user AJ565
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2110
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Location
San Antonio, TX US
AJ565 6/30/2019 2:19pm
6/30/2019 2:19pm
Here is what I mean about the plug. This is when I was running C12. The 2mm ring at the base is the correct way to know if your jetting is right.

Also my dyno graph running U4.4



1
lukemoto
Profile picture for user lukemoto
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256
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8/8/2018
Location
Mukwonago, WI US
lukemoto 6/30/2019 2:53pm
6/30/2019 2:53pm
lukemoto wrote:
[img]https://p.vitalmx.com/photos/forums/2019/06/30/357326/s1200_20190629_092549.jpg[/img] Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax...

Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax but the cool factor helped me decide to try it.
AJ565 wrote:
I have one and it’s setup with the trax system off. IMO it’s a noticeable step up from a stock shock, but I feel a revalve...
I have one and it’s setup with the trax system off. IMO it’s a noticeable step up from a stock shock, but I feel a revalve with a bladder conversion is almost on the same level and more affordable for most. As in I don’t think most would notice any difference between the two it’s that close. The stock shock works really well on these bikes once it’s setup for the rider. I think the best suspension improvement to my bike was the ride engineering performance link out back and the cone valves.
Agreed its really not necessary, however I went from a completely stock shock and forks to CV and trax and the feeling of comfort as in I feel super connected with the bike now. And I'm guilty of enjoying the "bling"
Did you feel like the bike sat lower with the trax? I've been running 107mm on both shocks mostly hard pack and the trax feels lower and I really like that.
AJ565
Profile picture for user AJ565
Posts
2110
Joined
3/12/2012
Location
San Antonio, TX US
AJ565 6/30/2019 3:04pm
6/30/2019 3:04pm
lukemoto wrote:
[img]https://p.vitalmx.com/photos/forums/2019/06/30/357326/s1200_20190629_092549.jpg[/img] Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax...

Trax shock is a huge improvement imo for this bike. the stock shock is really good and there is no way I needed a trax but the cool factor helped me decide to try it.
AJ565 wrote:
I have one and it’s setup with the trax system off. IMO it’s a noticeable step up from a stock shock, but I feel a revalve...
I have one and it’s setup with the trax system off. IMO it’s a noticeable step up from a stock shock, but I feel a revalve with a bladder conversion is almost on the same level and more affordable for most. As in I don’t think most would notice any difference between the two it’s that close. The stock shock works really well on these bikes once it’s setup for the rider. I think the best suspension improvement to my bike was the ride engineering performance link out back and the cone valves.
lukemoto wrote:
Agreed its really not necessary, however I went from a completely stock shock and forks to CV and trax and the feeling of comfort as in...
Agreed its really not necessary, however I went from a completely stock shock and forks to CV and trax and the feeling of comfort as in I feel super connected with the bike now. And I'm guilty of enjoying the "bling"
Did you feel like the bike sat lower with the trax? I've been running 107mm on both shocks mostly hard pack and the trax feels lower and I really like that.
No it sits the same. ClubMX and PowerBand both told me to set the sag at 103 so that’s where mine is at. No swap through braking or acceleration bumps, my bike is solid everywhere. That’s what I ran the stock shock at too. I went to cones and then a few months later added the trax so that’s why I noticed the rear shock more changing one part at a time.
Rick Amatuzio 5/27/2020 5:03am
5/27/2020 5:03am
mx4all wrote:
[img]https://p.vitalmx.com/photos/forums/2019/06/12/353755/s1200_20190605_212119.jpg[/img] Bought a new bike recently so I figured I would do a thread in here to get some info on how to set it up...


Bought a new bike recently so I figured I would do a thread in here to get some info on how to set it up.
Haven't ridden 2 strokes in 15 years.

Bought it with 20 hours on it. The previous owner put on a HGS exhaust and let a shop tune it and benched it.





I have done two practices on the bike and she hits like a mother f***er and screams like a bit*h.
I have never got this tired trying hold on to any previous bike. Got to put on a seat with better grip I guess.

I saw on the bench papers that I got the red spring in it so I will try the yellow and the green next time and see how it feels.
Unfortunately those dyno graphs are all wrong and inaccurate. How do people get away with this?? Torque all equals HP at 5250. Torque X RPM / 5250 = HP. No exceptions unless someone Is manipulating things.. still the best bike I’ve get had is this bike!

Pit Row

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