KTM 125 OR KTM 150

Bruce372
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Bruce372 10/9/2019 4:55pm
10/9/2019 4:55pm
jeffro503 wrote:
I had been seriously thinking of doing a 150 build either on my 125 ( 17' TC 125 ) or pick up a new 2020 Husky...
I had been seriously thinking of doing a 150 build either on my 125 ( 17' TC 125 ) or pick up a new 2020 Husky and doing the build on that. My issue with the 150 is lack of over-rev , since my 125 screams compared to one.

I'm wondering if it's possible to do a bunch of port work , as to keep the 150 bottom power , but add in some over-rev that's similar to my 125? If that isn't possible , then I'm definitely sticking with the 125. To me , the top end , over shadows the lack of low end grunt.
Bruce372 wrote:
Get the 150 kit, they make loads of top end power. If you dont like it, I'll buy it off you. $850 for that kit really...
Get the 150 kit, they make loads of top end power.

If you dont like it, I'll buy it off you.

$850 for that kit really is a bargain for what you get.... but anyone claiming a 58mm 144 won't rev, obviously hasn't ridden a well setup one.
jeffro503 wrote:
Thanks Bruce ( and you other two ). I have been able to ride a pretty new 19' SX150. Fellow members and good buddy of mine...
Thanks Bruce ( and you other two ). I have been able to ride a pretty new 19' SX150. Fellow members and good buddy of mine ( IanMac 138 ). I loved the bottom end on his bike , but definitely liked my mid range and top a lot more on my 125. We swapped for a practice and he even said he couldn't believe the over-rev on my bike. On a tiddler , it's extremely important in my eyes.

I'm out with an injury right now , and my season is pretty much wrecked , but will definitely think about doing a modified 150 build. Not really sure I need a 2020 , so I'll probably mod the one I have and see what happens.
That might be jetting and not porting Jeff.

I am doing the stic carb conversion on my kids 125 right now, so finally I'll be able to do real back to back comparison.

When i still had my rm144, we were both convinced the rm had more top end over his stock 125 husky
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jeffro503
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jeffro503 10/9/2019 5:03pm
10/9/2019 5:03pm
I'm running a STIC modded pwk36 on my 125 now as well. High compression head , good exhaust , opened air box , vforce Reed's and using race fuel. I noticed the biggest difference out of anything , was when the stic was installed. It was like I had sent my motor off to PC. Was a power gain every where. Even added " more " over-rev. No port work done on my 125 , and it rips harder than anything I could have imagined.
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Bruce372
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Bruce372 10/10/2019 1:08pm
10/10/2019 1:08pm
jeffro503 wrote:
I'm running a STIC modded pwk36 on my 125 now as well. High compression head , good exhaust , opened air box , vforce Reed's and...
I'm running a STIC modded pwk36 on my 125 now as well. High compression head , good exhaust , opened air box , vforce Reed's and using race fuel. I noticed the biggest difference out of anything , was when the stic was installed. It was like I had sent my motor off to PC. Was a power gain every where. Even added " more " over-rev. No port work done on my 125 , and it rips harder than anything I could have imagined.
And there we have it, I am sure there are plenty if people that say a 36mm carb won't rev, but you've actually tried it and found it does.
HighPlainsSquid 10/10/2019 4:38pm
10/10/2019 4:38pm Edited Date/Time 10/10/2019 4:41pm
burn1986 wrote:
Well, that’s half true. The 2015 (and earlier models) was a purpose-built 150 (144) with a different engine, pipe, cylinder, etc from the 125. The ‘15...
Well, that’s half true. The 2015 (and earlier models) was a purpose-built 150 (144) with a different engine, pipe, cylinder, etc from the 125. The ‘15 was a “true” 150, unlike today’s, which is a 125 with a 144 kit bolted on (bored/replated cylinder and piston). The ‘15 retained all the good characteristics of a 125 but with more power everywhere.
My son is surprised to find out that his '19 150 SX won't rev. Smile

But, seriously, yes, I know all this. Thing is... I _can't_ ride the 150 like a 125 so it's kind of a moot point. I ride it more like a 250 that's not gonna cartwheel down the track when I'm tired and grab too much throttle. I am just a 57 year old squid, you know?

FWIW, I had a '05 KX 144 for a year, too... it was okay, but I honestly wish I'd just left it like a 125.

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Bruce372
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Bruce372 10/13/2019 6:16pm
10/13/2019 6:16pm
Ok, we have both a 2018 sx150, and a 2018 tc125.

Today I rode them both now equipped with the same pwk stic carb, same pipe, silencer, fuel and both engines stock.

Both are amazing bikes, and if you cant have fun on either or feel one outshines the other then more fool you, lol.

The 125 feels a little freer revving and vibes slightly less, but on the flip side the 150 growls out of corners and has already done a lot of work before the 125 is revving past peak.

The interesting thing, when we replaced our top end screaming rm144 with the tc125, the Tc didn't rev out as well. Inwas somewhat surprised with the stic mod because now it really screams. Maybe a tad more than the 150, but the 150 isn't really running out of steam like some bikes do

Anyone in nor cal more than welcome to try them both
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erik_94COBRA
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erik_94COBRA 10/14/2019 7:03pm
10/14/2019 7:03pm
Bruce372 wrote:
Ok, we have both a 2018 sx150, and a 2018 tc125. Today I rode them both now equipped with the same pwk stic carb, same pipe...
Ok, we have both a 2018 sx150, and a 2018 tc125.

Today I rode them both now equipped with the same pwk stic carb, same pipe, silencer, fuel and both engines stock.

Both are amazing bikes, and if you cant have fun on either or feel one outshines the other then more fool you, lol.

The 125 feels a little freer revving and vibes slightly less, but on the flip side the 150 growls out of corners and has already done a lot of work before the 125 is revving past peak.

The interesting thing, when we replaced our top end screaming rm144 with the tc125, the Tc didn't rev out as well. Inwas somewhat surprised with the stic mod because now it really screams. Maybe a tad more than the 150, but the 150 isn't really running out of steam like some bikes do

Anyone in nor cal more than welcome to try them both
Sent my '14 150SX carb off to George today. Going to get the new tube and JD Jetting installed on it.

I currently have a TMX from my TC250 installed on it so will report the back to back comparison.
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Bruce372
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Bruce372 10/15/2019 7:54am
10/15/2019 7:54am
Bruce372 wrote:
Ok, we have both a 2018 sx150, and a 2018 tc125. Today I rode them both now equipped with the same pwk stic carb, same pipe...
Ok, we have both a 2018 sx150, and a 2018 tc125.

Today I rode them both now equipped with the same pwk stic carb, same pipe, silencer, fuel and both engines stock.

Both are amazing bikes, and if you cant have fun on either or feel one outshines the other then more fool you, lol.

The 125 feels a little freer revving and vibes slightly less, but on the flip side the 150 growls out of corners and has already done a lot of work before the 125 is revving past peak.

The interesting thing, when we replaced our top end screaming rm144 with the tc125, the Tc didn't rev out as well. Inwas somewhat surprised with the stic mod because now it really screams. Maybe a tad more than the 150, but the 150 isn't really running out of steam like some bikes do

Anyone in nor cal more than welcome to try them both
erik_94COBRA wrote:
Sent my '14 150SX carb off to George today. Going to get the new tube and JD Jetting installed on it. I currently have a TMX...
Sent my '14 150SX carb off to George today. Going to get the new tube and JD Jetting installed on it.

I currently have a TMX from my TC250 installed on it so will report the back to back comparison.
Looking to hear your feedback Erik. The mikini is a good carb, but dang the stic setup is fast
Bruce372
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Bruce372 10/15/2019 7:57am
10/15/2019 7:57am
Keeping off tangent, lol. There are a few top amateurs in norcal and I've spoke to their dads and a lot have gone to keihin carb. Check out the screen grab from Vollhands latest video

FWIW the last euro put bits, all the top factory husky and ktm 125s were running mikuni


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STIC
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STIC 10/15/2019 2:38pm
10/15/2019 2:38pm
Stic Headquarters; yes the STIC is the hot set-up with the 2.870mm tube (aka .113") with STIC Jetting kit.
Bruce372
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Bruce372 10/16/2019 11:09am
10/16/2019 11:09am
DynoDan22 wrote:
Bruce372: Classic! Hahahaha! My '18 150sx must have been a magical over-square engine that actually revved! Peak and over-rev was incredible on that bike. Maybe I...
Bruce372: Classic! Hahahaha! My '18 150sx must have been a magical over-square engine that actually revved! Peak and over-rev was incredible on that bike. Maybe I stumbled on the perfect powervalve spring and adjustment and thirty six iterations of Mikuni getting specs (S1 or S4 nozzle?) and finally did the impossible! I got an over-square small bore to rev!!! Hahaha
Hi Dan- would you be prepared to share your final jetting spec on the 150SX mikuni carb?

Thanks, Bruce
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DynoDan22 10/16/2019 12:38pm
10/16/2019 12:38pm Edited Date/Time 10/16/2019 12:39pm
Bruce372:

AS: 1.75-2.0 turns out
Pilot: 45
Needle: NOZG (3rd clip)
Main: 180 (182 if cooler than 65*F)
Slide: #7 (stock)
Float Height: (stock) 8mm

* Carb is OEM Keihin 38mm AG from '16 KTM150

Engine is all stock except:
-'16 OEM carb manifold
-Vforce4 reeds
-FMF Factory Fatty/Shorty

Fuel: 50:50 VP C12 and Shell Premium
Oil: Motorex Crosspower 2T @40:1

Ambient conditions (So Cal):
Altitude: 2,300-2,700ft
Temps 50-100*F (if cooler than 65*F use 182 main) use air screw for temp comp.

Other:
Twin Air filter/Twin Air filter oil
Piston Deck Height: -.0025" below cylinder deck @ TDC (stock)
Power Valve Spring/adj = stock PV spring @ .004" in from flush (all way out)
Bruce372
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Bruce372 10/16/2019 1:54pm
10/16/2019 1:54pm
DynoDan22 wrote:
Bruce372: AS: 1.75-2.0 turns out Pilot: 45 Needle: NOZG (3rd clip) Main: 180 (182 if cooler than 65*F) Slide: #7 (stock) Float Height: (stock) 8mm *...
Bruce372:

AS: 1.75-2.0 turns out
Pilot: 45
Needle: NOZG (3rd clip)
Main: 180 (182 if cooler than 65*F)
Slide: #7 (stock)
Float Height: (stock) 8mm

* Carb is OEM Keihin 38mm AG from '16 KTM150

Engine is all stock except:
-'16 OEM carb manifold
-Vforce4 reeds
-FMF Factory Fatty/Shorty

Fuel: 50:50 VP C12 and Shell Premium
Oil: Motorex Crosspower 2T @40:1

Ambient conditions (So Cal):
Altitude: 2,300-2,700ft
Temps 50-100*F (if cooler than 65*F use 182 main) use air screw for temp comp.

Other:
Twin Air filter/Twin Air filter oil
Piston Deck Height: -.0025" below cylinder deck @ TDC (stock)
Power Valve Spring/adj = stock PV spring @ .004" in from flush (all way out)
Hahaha, thanks Dan... I was actually wondering if you have a spec for the mikuni. No worries, this is great info... I was just looking for a mikuni spec for when i sell the bike.

Cheers, Bruce
DynoDan22
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DynoDan22 10/16/2019 2:34pm
10/16/2019 2:34pm
Bruce,

oops! Sorry! haha For the Mikuni, I went down 1 pilot jet and a half clip leaner on the needle than stock with all the above specs. It was close. The stock main jet was also close but on verge of being too lean.
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SmokinJoe439
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SmokinJoe439 10/16/2019 3:02pm
10/16/2019 3:02pm
That's what I about ended up with the short bit i was tasked to try and dail in this 19 150sx that had 8 hrs on it.

I ended up 2 down on the pilot 2nd clip pos stock main. It was better but it wasn't my bike and I only got to mess around with it for like an hour. It was also back in March so it was like low 40's temp wise.
arunkxf
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arunkxf 2/17/2020 6:28am
2/17/2020 6:28am Edited Date/Time 2/17/2020 6:29am
Trae_Arnold wrote:
After watching straight rhythm, I found a good deal on brand new KTM’s so I’m in the market for a 2 stroke. I’m coming off a...
After watching straight rhythm, I found a good deal on brand new KTM’s so I’m in the market for a 2 stroke. I’m coming off a 2018 CRF 250R, a bike that revs a ton like a 125. I’m a beginner rider and I’m not sure if I would like less power with more fun or almost the same amount of power and feel comfortable clearing jumps. Anyone ride both models of KTM’s that can give me some input?
I have a sx125 2015 and my dad has a sx150 2016.

Completely different bikes anyway because of the chassis/ motor changes, however if we're talking power there is definitely a big difference. The 150 feels a lot quicker, as mentioned by others on this thread the mid to top is where the power is on the 150. Wants to wheelie everywhere when I ride it.

It depends on your riding, I like the 125 as I can ride it a little more aggressive and it is forgiving. The 150 is closer to the 250f where if you're in the wrong gear it'll still pull etc... and easier to clear jumps.

I just love the 125, something about trying to use up as much power as you can from the bike
endurox
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endurox 2/19/2020 10:51am
2/19/2020 10:51am
SmokinJoe439 wrote:
That's what I about ended up with the short bit i was tasked to try and dail in this 19 150sx that had 8 hrs on...
That's what I about ended up with the short bit i was tasked to try and dail in this 19 150sx that had 8 hrs on it.

I ended up 2 down on the pilot 2nd clip pos stock main. It was better but it wasn't my bike and I only got to mess around with it for like an hour. It was also back in March so it was like low 40's temp wise.
Check the float level and buy the block gasket from JD jetting that is pinched on every 150 carb.
https://jdjetting.com/product/jdmk05-mikuni-tmx-jet-block-kit/.

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