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

swatdoc wrote:

Hey guys is there a consensus on the best pipe and silencer for the 150? Most people run the FMF Fatty, but how about the HGS...

Hey guys is there a consensus on the best pipe and silencer for the 150? Most people run the FMF Fatty, but how about the HGS or even Bill's? I know the FMF uses the same pipe for the 125 and 150. You'd think a dedicated 150 pipe would be a tad better.

I'm looking for a pipe that will give me a little wider powerband - not sign off as soon, but also not lose much torque (i'm a big/heavy guy). From what I understand a longer silencer is the way to go, but there's so many of them - does the brand really make a difference, or is it mostly the length?

AJ/Digger - really appreciate your work on the jetting. Gonna try these mods before thinking about the Keihin/STIC route.

Thanks

swatdoc wrote:

Bruce that is exactly what I was looking for. Actual test results instead of seat-of-the-pants opinions. One quick question though - if I was looking for...

Bruce that is exactly what I was looking for. Actual test results instead of seat-of-the-pants opinions.

One quick question though - if I was looking for more over rev, would I be better with PC’s longer silencer? Did you happen to test that with the FMF Fatty?

Thanks!

swatdoc wrote:

Bruce that is exactly what I was looking for. Actual test results instead of seat-of-the-pants opinions. One quick question though - if I was looking for...

Bruce that is exactly what I was looking for. Actual test results instead of seat-of-the-pants opinions.

One quick question though - if I was looking for more over rev, would I be better with PC’s longer silencer? Did you happen to test that with the FMF Fatty?

Thanks!

86rustbucket wrote:

Thanks to all that contributed to this thread, AJ, you saved me from drop kicking our 125 off a cliff. But, I am looking for a...

Thanks to all that contributed to this thread, AJ, you saved me from drop kicking our 125 off a cliff. But, I am looking for a bit more advice. I bought it with all of the stock jetting other than the PO installed the 43-75 needle. Current specs are

2018 125sx
FMF pipe
FMF Powercore 2.1 silencer
5.0 slide
S4 needle jet
42-74 needle 3rd clip (tried 2nd)
35 pilot jet (tried 32.5)
500 main (tried 490)
1.5 turns out pilot screw
1.75 turns in PV
Replaced the jet block gasket at 30 hours, 9 hours on the new jet block gasket
40:1 93 octane pump gas, Motorex 2t

Weather has been on the chilly side here most of the riding season so far, ranging from high 40s to high 50s, we are on a temp upswing now, elevation is 800 ft. My question is now the main, I ran a chop test on Sunday, it hurt to cut a brand new plug BtW, soot ring is really light and narrow, about 1.3 mm. I feel like the main might be a little lean. I just bought a KTM spec 520 main, for some reason they skip the 510. I haven’t seen anyone using the 520, wanted to get some feedback before trying it. I just don’t want to run too lean at WOT, based on this thread, it seems like 500 should be plenty. My other thought was maybe running 50:1 for a richer mixture, or maybe just leaving it alone as the temps rise this summer. The pipe is the raw finish and it gets blue, really blue after a few motos.

huckster mcplush wrote:

I have been tinkering around with this jetting for a little bit and have been pretty happy with it although I still think for my riding...

I have been tinkering around with this jetting for a little bit and have been pretty happy with it although I still think for my riding style I am still a bit too rich. Still getting a ton of spooge and occasionally will load up a little bit. Is anybody else riding the 150 in a more aggressive Trail manner? Currently bike specs are as follows...

Temps between 50 and 95f
Elevation usually around 1k
2017 KTM 150 xcw
Mikuni tmx 38
Fixed jet block gasket
Float height set
S4 needle jet
32.5 pilot
42-74 on 2nd clip pos
Air screw 2 turns out
490 main
Rk Tek head insert for 88 pump gas
Fmf fatty pipe
Fmf turbinecore 2.1 spark arrestor
Vforce 4 reed cage
Klotz tcw3 motorcycle (kl-302) @ 40:1

It's hard to describe what kind of Rider I am but I will link a YouTube video of my last race for reference if anybody would care to watch to give a better recommendation for me. This is about as aggressive and how hard this bike ever gets ridden so it should give some guidance I hope. The video is rather long but only the first couple minutes should summarize how this thing is being ridden. Aside from my racing style I also ride the bike on more slow and Technical terrain and some trials style riding as well Thanks so much for the help :-) ... Also worth mentioning that I do have my power valve adjuster screwed in a little bit to delay the hit. Running the yellow spring at about 3 full turns in from fully counterclockwise.

https://youtu.be/AI-1pZWNWZM

huckster mcplush wrote:

I have been tinkering around with this jetting for a little bit and have been pretty happy with it although I still think for my riding...

I have been tinkering around with this jetting for a little bit and have been pretty happy with it although I still think for my riding style I am still a bit too rich. Still getting a ton of spooge and occasionally will load up a little bit. Is anybody else riding the 150 in a more aggressive Trail manner? Currently bike specs are as follows...

Temps between 50 and 95f
Elevation usually around 1k
2017 KTM 150 xcw
Mikuni tmx 38
Fixed jet block gasket
Float height set
S4 needle jet
32.5 pilot
42-74 on 2nd clip pos
Air screw 2 turns out
490 main
Rk Tek head insert for 88 pump gas
Fmf fatty pipe
Fmf turbinecore 2.1 spark arrestor
Vforce 4 reed cage
Klotz tcw3 motorcycle (kl-302) @ 40:1

It's hard to describe what kind of Rider I am but I will link a YouTube video of my last race for reference if anybody would care to watch to give a better recommendation for me. This is about as aggressive and how hard this bike ever gets ridden so it should give some guidance I hope. The video is rather long but only the first couple minutes should summarize how this thing is being ridden. Aside from my racing style I also ride the bike on more slow and Technical terrain and some trials style riding as well Thanks so much for the help :-) ... Also worth mentioning that I do have my power valve adjuster screwed in a little bit to delay the hit. Running the yellow spring at about 3 full turns in from fully counterclockwise.

https://youtu.be/AI-1pZWNWZM

FGR01 wrote:

You didn't mention if you have changed the slide. The 5 slide would be very important in that type of tight riding with so much 1/8...

You didn't mention if you have changed the slide. The 5 slide would be very important in that type of tight riding with so much 1/8 - 1/2 throttle. Would likely alleviate the spooge and loading up quite a bit.

AJ565 wrote:

Also it might help you to switch what oil you’re using. Personally I run amsoil dominator and have never had any problems with it. The TCW3...

Also it might help you to switch what oil you’re using. Personally I run amsoil dominator and have never had any problems with it. The TCW3 has a pretty high flash point so the oil isn’t completely burning since you’re never really in the high rpm range. Here is a good chart to see and try another oil.

huckster mcplush wrote:

Crap. Forgot to mention that haha. Yes running the number 5 slide.

huckster mcplush wrote:

Crap. Forgot to mention that haha. Yes running the number 5 slide.

digger wrote:

You didn’t mention if you notched the front side of the slide or not. If you haven’t? I would recommend that you do so, and then...

You didn’t mention if you notched the front side of the slide or not. If you haven’t? I would recommend that you do so, and then decrease the pilot to a 30 or possibly a 27.5 in the heat.

swatdoc wrote:

Hey Digger - I've ordered the parts for the stock carb. I'm gonna cut down the slide myself to save money (I have a PWK/STIC on...

Hey Digger - I've ordered the parts for the stock carb. I'm gonna cut down the slide myself to save money (I have a PWK/STIC on order, but want to dial in the stock Mikuni first to have a comparison).

here's a pic I made with exaggerated dimensions just for illustration purposes. Which is the correct way to file the arch in the slide, A or B?

Are the slides marked by any chance? Or is there a way to confirm what the stock slide is before I take the Dremel to it - just in case KTM changes the slide on the 2022s?