125/150/250/300 KTM/HUS/GG jetting thread

riv187
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riv187 10/13/2021 7:22am
10/13/2021 7:22am
Hammer 663s wrote:
I just ordered an RK Tek head insert for our 2020 150Sx. It will be setup for 98-100 octane running a 92 non-eth + Sunoco 110...
I just ordered an RK Tek head insert for our 2020 150Sx. It will be setup for 98-100 octane running a 92 non-eth + Sunoco 110 blend @ 40:1 w/Motul 800. I expect to have to go to a 520 main and a 35 pilot. Kelsey at RK said throw fuel at it till it can't take anymore then back off a little. I'll report back on how it worked out.

Hammer 663s
riv187 wrote:
Kelsey made me a one off insert for my 18 TC125,,,,,I like it. I run straight 110 race gas,,so it's high compression. I feel like it...
Kelsey made me a one off insert for my 18 TC125,,,,,I like it. I run straight 110 race gas,,so it's high compression. I feel like it improved the bottom and gave my bike a wider power delivery. Buds HGS pipe/silencer and stock porting. I only race MX,,but like a smooth pull coming out of tight slippery corners and RK Tek delivered.
Hammer 663s wrote:
That's exactly what I am looking for but on less octane. We are mx only too. Stock pipe, FMF shorty, stock porting/reeds. Might do reeds and...
That's exactly what I am looking for but on less octane. We are mx only too. Stock pipe, FMF shorty, stock porting/reeds. Might do reeds and porting when it's time for a replate on the jug.

Where did you end up with jetting?
I also have the v force,,but stock porting. I found that my bike,,with the Buds pipe and matching shorty silencer,,needs the power valve turned in 4 turns if I remember. Trying to run less gave me a bog.
32.5 pilot,42-75 needle top clip,S-7 nozzle,,,and ground my slide to a 5.5. I run a 450 o 460 main but I welded a boss on back and installed a adjustable power jet. That gives me about a 4 main jet adjustment at twist of knob,,I have it turned out 1.5-2.5 turns most time. I would guess thats about a 480 main +/-
My idea was the buds pipe stretches top end,the power jet tuned for the time I ride adds top end,,the compression adds mid punch,,and vforce and rk head improve low end response.
..

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Hammer 663s
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Hammer 663s 10/13/2021 8:35am
10/13/2021 8:35am
riv187 wrote:
I also have the v force,,but stock porting. I found that my bike,,with the Buds pipe and matching shorty silencer,,needs the power valve turned in 4...
I also have the v force,,but stock porting. I found that my bike,,with the Buds pipe and matching shorty silencer,,needs the power valve turned in 4 turns if I remember. Trying to run less gave me a bog.
32.5 pilot,42-75 needle top clip,S-7 nozzle,,,and ground my slide to a 5.5. I run a 450 o 460 main but I welded a boss on back and installed a adjustable power jet. That gives me about a 4 main jet adjustment at twist of knob,,I have it turned out 1.5-2.5 turns most time. I would guess thats about a 480 main +/-
My idea was the buds pipe stretches top end,the power jet tuned for the time I ride adds top end,,the compression adds mid punch,,and vforce and rk head improve low end response.
..

Well that's about as one-off a setup as you can have! I'm trying to stay as close to "stock" with the carb as I can. I don't want a Lectron or a Stic setup. Yeah, maybe I can get more power with them but at our level I value simplicity and reliability over pure power. So far the base spec listed here is awesome for us. I did go to a 500 MJ since we are running a T2 blend. Bike ruins crisp and clean as it is now. Hoping the RK insert will broaden the power and just pull a little better everywhere.

In a year or so I will sell my 350 and this 150 will be come my primary bike. I'll be 60 and it's time to just have fun. I'm kinda building it the way I will want it when it's mine. The boy will move to a 250 and I'll be done buying bikes for a while. HAHAHAHAHA right. Smile

Hammer 663s
1
matt1992425freed 10/14/2021 2:35am
10/14/2021 2:35am
Whereabouts are people setting their float height? I've currently got mine around 8.5 but I just wondered if that would make it too lean as ktm recommend around 6.5
AJ565
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AJ565 10/14/2021 6:26am
10/14/2021 6:26am
matt1992425freed wrote:
Whereabouts are people setting their float height? I've currently got mine around 8.5 but I just wondered if that would make it too lean as ktm...
Whereabouts are people setting their float height? I've currently got mine around 8.5 but I just wondered if that would make it too lean as ktm recommend around 6.5
I set my floats perpendicular to the base of the carb body. I’ve never measured anything and have had zero problems.
1

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Bart149
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Bart149 10/26/2021 9:36am
10/26/2021 9:36am
My son has a 2019 KTM 125. I have it jetted alright with the stock jets provided. But it is still not good. So, I ordered all the parts so I can try the jetting listed on page one. Should be here sometime this week. But I live in western Wisconsin and it’s starting to get cold up here. We will start riding indoors at the Sandbox Arena in a few weeks. But in Dec.- Jan. it can be 20 to 30 degrees inside the arena. An idea on what adjustments I will need to make to the jetting for those temps. I know enough about jetting to be dangerous. I run Maxima K2 at 40:1. I run a pump gas/race gas mix.
riv187
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riv187 10/26/2021 10:21am
10/26/2021 10:21am
Bart149 wrote:
My son has a 2019 KTM 125. I have it jetted alright with the stock jets provided. But it is still not good. So, I ordered...
My son has a 2019 KTM 125. I have it jetted alright with the stock jets provided. But it is still not good. So, I ordered all the parts so I can try the jetting listed on page one. Should be here sometime this week. But I live in western Wisconsin and it’s starting to get cold up here. We will start riding indoors at the Sandbox Arena in a few weeks. But in Dec.- Jan. it can be 20 to 30 degrees inside the arena. An idea on what adjustments I will need to make to the jetting for those temps. I know enough about jetting to be dangerous. I run Maxima K2 at 40:1. I run a pump gas/race gas mix.
I put a powerjet on mine as seen on previous pictures just for quickly dialing in main jet on cold morning vs hot afternoons...We do get 40s in mornings during winter here in Florida and it can seize a bike if you don't richen it up,,,but then the sun comes out and 60s-70s mid afternoon,,
I'd go about 3 up on main and possibly 1 clip on needle,,,and in on the airscrew. I'd try the 'easy' before I'd go and revamp the nozzle/jet needle configuration.
AJ565
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AJ565 10/26/2021 11:12am
10/26/2021 11:12am
When it drops to 30-40’s here on my 250 I have to move the needle one clip and go up one size on the pilot jet. I’d expect similar on the 125’s as well.
Bart149
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Bart149 10/26/2021 11:23am
10/26/2021 11:23am
I will give that a try. I was thinking my be a 500-520 main jet and a 35 pilot and down one clip. But that might be to big of a swing at it? I will play around with it when it gets colder out. Thanks for the help.
AJ565
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AJ565 10/26/2021 6:17pm
10/26/2021 6:17pm
Bart149 wrote:
I will give that a try. I was thinking my be a 500-520 main jet and a 35 pilot and down one clip. But that might...
I will give that a try. I was thinking my be a 500-520 main jet and a 35 pilot and down one clip. But that might be to big of a swing at it? I will play around with it when it gets colder out. Thanks for the help.
These bikes love fuel, you probably can get away with a 500 now.
Bart149
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Bart149 10/27/2021 7:20am
10/27/2021 7:20am
Is this what the needle looks like? Straight piece on the end?
Bart149
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Bart149 10/27/2021 7:24am
10/27/2021 7:24am
This is what the number 5 slide from JD Jetting Looks like. Notch on back is very small. Sorry for the blurry photo.


digger
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digger 10/27/2021 9:39am
10/27/2021 9:39am
Bart149 wrote:
Is this what the needle looks like? Straight piece on the end? [img]https://p.vitalmx.com/photos/forums/2021/10/27/516267/s1200_Needle.jpg[/img]
Is this what the needle looks like? Straight piece on the end?
Yes, it looks like an oem 42-74 needle and an factory notched TMX-x slide. I like to open up the notch a little more to make the pilot circuit a little more efficient, but it's not absolutely necessary.
Bart149
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Bart149 10/27/2021 12:18pm
10/27/2021 12:18pm
I am afraid it will mess up the plating? It looks like chrome plating. Is the stock one just polished?
digger
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digger 10/28/2021 7:18am
10/28/2021 7:18am
Bart149 wrote:
I am afraid it will mess up the plating? It looks like chrome plating. Is the stock one just polished?
I've cut and notched alot of Mikuni slides, and have not seen any damage to the slides chroming caused from the cutting. I've had many slides come to me with more wear to the slide chroming than i would expect from a 1-3 year old slide though. I've seen lots of TPS Mikuni TMX-x slides that were cracked and or missing pieces from them.
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hylo 11/1/2021 11:04am
11/1/2021 11:04am
Jetted my 250 as this thread said today. Even went through the trouble to order the slide from Kawasaki. The bike ran great! Crisp and plenty overrev.

Thanks to the guys researching and tinkering with this stuff!
1
yellow97tt6spd 11/25/2021 5:46am
11/25/2021 5:46am
Hello all,

Two of my friends recently picked up 150sx’s (a 19 and a 22). I tried running through this thread quick to see what’s considered the best default pipe and silencer setup (for intermediate MX), and I didn’t see it. I know on my 18 250sx the PC pipe and long silencer seemed to be the “go to”.

Is there a “go to” for the 150s?

Thanks in advance!
FGR01
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FGR01 11/25/2021 6:15am
11/25/2021 6:15am
yellow97tt6spd wrote:
Hello all, Two of my friends recently picked up 150sx’s (a 19 and a 22). I tried running through this thread quick to see what’s considered...
Hello all,

Two of my friends recently picked up 150sx’s (a 19 and a 22). I tried running through this thread quick to see what’s considered the best default pipe and silencer setup (for intermediate MX), and I didn’t see it. I know on my 18 250sx the PC pipe and long silencer seemed to be the “go to”.

Is there a “go to” for the 150s?

Thanks in advance!
There is no "gotta have" for the 125/150. It's more a pick your flavor. The FMF and Bill's pipes look identical to each other. Either of them with a shorty will make the bike feel punchier and with less over rev. I'm usually running the FMF with the normal length FMF silencer which is the same length as the stock silencer.

Jetting and power valve adjustment will make much more noticeable difference than changing the pipe.
queen of spodes 11/25/2021 8:09pm
11/25/2021 8:09pm
AJ/others what brand/type of premix are you using with 250/300 updated jetting option A?

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AJ565
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AJ565 11/25/2021 8:18pm
11/25/2021 8:18pm
Amsoil dominator is all I’ve ever run in my bike.
1
crawfishoo 11/26/2021 6:44am
11/26/2021 6:44am
Motorex 2T at 50:1 with recreational 90 (ethonal free). If you keep the head stock pump gas has sufficient octane. It will run more crisp on race fuel but it's not necessary.
bsbrits
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bsbrits 11/27/2021 6:07am
11/27/2021 6:07am
My 2022 has the S7 nozzle. Should I get the S4?

My damn bike bogs, spooges, sputters and will not start below 30 degrees. I'm in Pittsburgh, PA about 1200ft above sea level.
AJ565
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AJ565 11/27/2021 8:21am
11/27/2021 8:21am
bsbrits wrote:
My 2022 has the S7 nozzle. Should I get the S4? My damn bike bogs, spooges, sputters and will not start below 30 degrees. I'm in...
My 2022 has the S7 nozzle. Should I get the S4?

My damn bike bogs, spooges, sputters and will not start below 30 degrees. I'm in Pittsburgh, PA about 1200ft above sea level.
Yes. That cold you’ll also need to move the clip in the needle down to richen it up and up a size on the pilot jet. Try two down and see how it runs. I’ve only tested in the upper 30’s and had to go one clip.
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bsbrits 11/27/2021 2:53pm
11/27/2021 2:53pm
AJ,
Do you still recommend starting with the following settings from page 1. I have a 2022 125sx. I went back to running the Stock jetting. I just couldn't get it right. It spooges, hard to start, bogs when you rip the throttle. Dont get me started about the way it acts when cold outside.

I guess I need the summer baseline numbers first, before messing with it in the cold. I suck at jetting.

I will be ordering the 5.0 slide, 42-74 and S4. Did I miss anything?

Here are your settings
MJ 490
PJ 32.5
Needle Jet S4
AS 1.5
slide 5.0
Needle 42-74 on the 2nd clip (Yamaha 284-14116-H4-00)
Needle jet S4 (KTM part #55431021400)
PV 1.75 turns in from all the way out.
Fuel mix 40:1

Here are my current settings. Runs like sh**.

Mikuni TMX38, TMX 38 87
Needle 43-71
Main 500
Idle jet 35
Needle s7
AS 1.5
AJ565
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AJ565 11/27/2021 4:24pm
11/27/2021 4:24pm
bsbrits wrote:
AJ, Do you still recommend starting with the following settings from page 1. I have a 2022 125sx. I went back to running the Stock jetting...
AJ,
Do you still recommend starting with the following settings from page 1. I have a 2022 125sx. I went back to running the Stock jetting. I just couldn't get it right. It spooges, hard to start, bogs when you rip the throttle. Dont get me started about the way it acts when cold outside.

I guess I need the summer baseline numbers first, before messing with it in the cold. I suck at jetting.

I will be ordering the 5.0 slide, 42-74 and S4. Did I miss anything?

Here are your settings
MJ 490
PJ 32.5
Needle Jet S4
AS 1.5
slide 5.0
Needle 42-74 on the 2nd clip (Yamaha 284-14116-H4-00)
Needle jet S4 (KTM part #55431021400)
PV 1.75 turns in from all the way out.
Fuel mix 40:1

Here are my current settings. Runs like sh**.

Mikuni TMX38, TMX 38 87
Needle 43-71
Main 500
Idle jet 35
Needle s7
AS 1.5
The slide is the key to making all of this work. That’s the main problem. Being cold I’d keep that 500 and 35 pilot in to start and see how it runs. These bikes love fuel so the bigger the main you can get away with the better. For sure swap the rest of the parts.
need2ride
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need2ride 11/27/2021 4:43pm
11/27/2021 4:43pm
Thank you AJ- my 2019 125 rips with your jetting specs. I moved the clip to the 1st pos. and am running a 520 main. Thinking the bike could even handle a larger main jet...
AJ565
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AJ565 11/27/2021 7:01pm
11/27/2021 7:01pm
need2ride wrote:
Thank you AJ- my 2019 125 rips with your jetting specs. I moved the clip to the 1st pos. and am running a 520 main. Thinking...
Thank you AJ- my 2019 125 rips with your jetting specs. I moved the clip to the 1st pos. and am running a 520 main. Thinking the bike could even handle a larger main jet...
You can put as big of main as you want in it at this point, the bike doesn’t create enough vacuum to pull more fuel then a 520 main. Crazy to think that.
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FGR01
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FGR01 11/27/2021 8:21pm
11/27/2021 8:21pm
need2ride wrote:
Thank you AJ- my 2019 125 rips with your jetting specs. I moved the clip to the 1st pos. and am running a 520 main. Thinking...
Thank you AJ- my 2019 125 rips with your jetting specs. I moved the clip to the 1st pos. and am running a 520 main. Thinking the bike could even handle a larger main jet...
AJ565 wrote:
You can put as big of main as you want in it at this point, the bike doesn’t create enough vacuum to pull more fuel then...
You can put as big of main as you want in it at this point, the bike doesn’t create enough vacuum to pull more fuel then a 520 main. Crazy to think that.
On my 125, 520 to 540 I noticed a difference. 540 to 560, not so much.
queen of spodes 11/29/2021 11:18am
11/29/2021 11:18am
I have most of my parts here for the 250sx option "A" spec (not labeled, it's the first of the two options) in the first post.

Can this be done relatively easily without pulling the carb from the bike, by rotating carb in the air boots?
FGR01
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FGR01 11/29/2021 2:56pm
11/29/2021 2:56pm
queen of spodes wrote:
I have most of my parts here for the 250sx option "A" spec (not labeled, it's the first of the two options) in the first post...
I have most of my parts here for the 250sx option "A" spec (not labeled, it's the first of the two options) in the first post.

Can this be done relatively easily without pulling the carb from the bike, by rotating carb in the air boots?
It "can" be done, but you're better off just pulling the carb. Especially if you're replacing the jet block gasket, which I hope you are.

This will give you a chance to thoroughly clean the carb and make sure everything is right. Measure and verify the float height, etc.
1

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