Tell me about the 2017 KTM 250sx

queen of spodes
Edited Date/Time 12/6/2021 4:10am
Looking at picking up a 2017 KTM 250sx since my 07 KX250 is down until parts magically make it through the west coast ports.

What I learned from searching is it came with a Mikuni, vs Keihin in years prior. I think this was the first year with AER forks as well. I read somewhere that the 17 clutch case is badly designed and promotes kickstart shaft failure (18 clutch case fits and fixes that).

Is the Mikuni decent, or am I going to pull my hair out jetting. Current owner runs 927 at 32:1 and claims "usual amount of smoke". Couldn't see any spooge from pics, I should go look at it in person Wednesday.

How fiddly are AER forks? I'm tall and 185lbs. Anything weird about chassis and handling?

What else do I need to know about this gen 250sx?
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AJ565
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AJ565 11/22/2021 6:05pm
11/22/2021 6:05pm
There is a jetting thread on here. Follow it and live happily ever after.

Yes the ‘17 had a right side case problem. A longer bolt helps or replacing the case half if it breaks with a ‘18 case half fixes it. Other then that they are great bikes. I have around 120 hours on mine with one top end done at 90 hours just because. PC pipe and silencer helps a ton with over rev and a 14/52 gearing is the prime setup for a more useable 2nd and 3rd gear and also lets the rear suspension work better. The forks are trash. Get them revalved and updated parts put in and it helps a ton.
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queen of spodes 11/22/2021 6:07pm
11/22/2021 6:07pm
Are AER fork revalves a ton more expensive or pretty much the same? Will most shops know how to work on them?
AJ565
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AJ565 11/22/2021 6:11pm
11/22/2021 6:11pm
About the same. Most shops I’m not sure. Big name shops like Powerband, FC, Enzo, ect will know what they’re doing. I’ve personally only used Powerband with my KTM suspension and have always been happy and the setting have been spot on.
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Rickyisms 11/22/2021 6:16pm
11/22/2021 6:16pm
Ditto on powerband. Solid work on WP stuff.
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queen of spodes 11/22/2021 6:40pm
11/22/2021 6:40pm Edited Date/Time 11/22/2021 6:44pm
Are center cases NLA for 2017 250sx?

Not seeing actual case part numbers in the Engine Case section of the fiche

https://www.lexingtonmotorsports.com/--xpartsstream#/KTM/250_SX_ENGINE_…


N/M, guess the 17 cases are actually discontinued and not superceded, i found 18 cases:
https://www.ktmworld.com/oemparts/a/ktm/60102df187a8661fdc4c6a5f/engine…
rollin64caddy 11/22/2021 7:22pm
11/22/2021 7:22pm
I have a 17 tc250, I went with a keihin carb cause they seem less sensitive to altitude and temp changes. I haven't tried the jetting mentioned by aj565 but would bet money they are spot on. You can tap the threads in the case and install a longer bolt to solve those issues. I never could adapt to the air fork but that's my riding preference.
queen of spodes 11/22/2021 8:03pm
11/22/2021 8:03pm Edited Date/Time 11/22/2021 8:04pm
rollin64caddy wrote:
I have a 17 tc250, I went with a keihin carb cause they seem less sensitive to altitude and temp changes. I haven't tried the jetting...
I have a 17 tc250, I went with a keihin carb cause they seem less sensitive to altitude and temp changes. I haven't tried the jetting mentioned by aj565 but would bet money they are spot on. You can tap the threads in the case and install a longer bolt to solve those issues. I never could adapt to the air fork but that's my riding preference.
Are older generation SX forks a better bet and are they basically direct swaps? I mean I plan to ride with the AER fork to see of course...
queen of spodes 11/22/2021 8:55pm
11/22/2021 8:55pm
Seller of the bike I'm looking at got a bit huffy when I delicately asked if he knew if this bike had been warrantied. So, I may pass and seek out a '18.

Are 300's relatively easy to set up for moto?
AJ565
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AJ565 11/22/2021 9:08pm
11/22/2021 9:08pm
I’m considering selling my ‘18. It’s really clean and runs amazing. I’m in Texas just in case.
suspensionguy 11/23/2021 12:25am
11/23/2021 12:25am
I don’t think the cases are a reason to not buy a 17’. I sold my 17’ in 2019, it had 200 trouble free hours on it, and its still going, see the current owner often and it’s had no issues with the cases. The forks are easy to work on and any tuner other there should be familiar with them. I have two 20’ 250sx right now, one with a keihin and one with a mikuni, think I like how the mikuni runs more then the keihin.

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Bulldog
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Bulldog 11/23/2021 3:24am
11/23/2021 3:24am
We had the kickstarter break off the right case about a year after we purchased the bike new. We contacted KTM and they warrantied it. We do not have a KTM dealer close to us so they sent out a Factory Rep and he replaced the cases in our garage at no cost. We did pay for the gasket kit. They 2017 were cases discontinued. If it breaks, the fix is the 2018 cases. We have had no issues with he 2018 cases. I added a picture showing the bike cases in action this year at the 2021 Sumter Enduro.




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wydopen
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wydopen 11/23/2021 4:18am
11/23/2021 4:18am
I got a 17 350 and was pleasantly surprised how the Enzo revalved forks worked. Track was fairly smooth though. From reading stuff online I expected them to be borderline unrideable but they had great holdup even though I was running pretty low pressure..That said I’m doing a kyb conversion
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seth505
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seth505 11/23/2021 7:30am
11/23/2021 7:30am
Great bikes, just watch the case as mentioned. Bike always ran great and no issues (after settling on some good jetting). I liked the AER forks and when it was time to freshen up my shock I had Enzo do a front/rear revalve for under $500.
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suspensionguy 11/23/2021 10:57am
11/23/2021 10:57am
AJ565 wrote:
I’m considering selling my ‘18. It’s really clean and runs amazing. I’m in Texas just in case.
queen of spodes wrote:
Not an easy way to DM people here can you shoot me a message at i_dig_dirt@agirlandhertractor.com ?
From reading AJ’s posts, I’d be willing to bet his is dialed and well taken care of, would be a great buy.
queen of spodes 11/24/2021 7:18pm
11/24/2021 7:18pm
Went ahead and got it

Graphics, wheel set, tires, PC pipe, and JD Jetting kit are on the way. Will set up a build thread shortly.
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AJ565
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AJ565 11/24/2021 9:11pm
11/24/2021 9:11pm
Cancel the JD jet kit. It’s garbage.
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queen of spodes 11/25/2021 5:05am
11/25/2021 5:05am
AJ565 wrote:
Cancel the JD jet kit. It’s garbage.
The internet is an interesting place. Googling shows a ton of positive feedback on the kit, then other folks say don't do it.

Anyone have details on why the JD kit is either worthy or trash?
Pirate421
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Pirate421 11/25/2021 5:23am
11/25/2021 5:23am Edited Date/Time 11/25/2021 5:24am
I had a jd kit on my 2014 250sx, I know a different carb and everything but I really liked it. Bike ran great, I even put that on after I had one of the old model lectrons on there and the jd kit felt much better. For under $100 it’s worth a try I’d say. Easy to follow directions and takes like 5 minutes to set up. I can’t see it making it worse.
queen of spodes 11/25/2021 5:47am
11/25/2021 5:47am
Pirate421 wrote:
I had a jd kit on my 2014 250sx, I know a different carb and everything but I really liked it. Bike ran great, I even...
I had a jd kit on my 2014 250sx, I know a different carb and everything but I really liked it. Bike ran great, I even put that on after I had one of the old model lectrons on there and the jd kit felt much better. For under $100 it’s worth a try I’d say. Easy to follow directions and takes like 5 minutes to set up. I can’t see it making it worse.
The bike I bought felt super rich on the bottom, almost blubbery like an old 500 2 stroke. I'd read so many positive reviews of the JD kit I figured it would be worth a go.

Like the idea of better mileage with the Lectron but worry I'd be in the same fiddly jetting mess as a standard carb.
Richy
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Richy 11/25/2021 6:06am
11/25/2021 6:06am Edited Date/Time 11/25/2021 6:07am
AJ's jetting spec made mine a different bike, I've done two more since for friends and can't fault it.

Weirdly this is over in the UK at sea level and cold as fuck, and still only minor tweaks to get it spot on.

Just in case the JD kit doesn't work out 👍
Pirate421
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Pirate421 11/25/2021 6:32am
11/25/2021 6:32am
queen of spodes wrote:
The bike I bought felt super rich on the bottom, almost blubbery like an old 500 2 stroke. I'd read so many positive reviews of the...
The bike I bought felt super rich on the bottom, almost blubbery like an old 500 2 stroke. I'd read so many positive reviews of the JD kit I figured it would be worth a go.

Like the idea of better mileage with the Lectron but worry I'd be in the same fiddly jetting mess as a standard carb.
The lectron ran and idled fine but the power just felt muted. A 250sx is super fast in the first place and way faster than I need but the difference between the conventional carb with good jetting and lectron was quite a bit. There is a possibility it wasn’t set up right but it felt pretty dialed no lean bogging or rich symptoms and just felt kind of dull.
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mikie44
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mikie44 11/25/2021 7:53am
11/25/2021 7:53am
Pirate421 wrote:
I had a jd kit on my 2014 250sx, I know a different carb and everything but I really liked it. Bike ran great, I even...
I had a jd kit on my 2014 250sx, I know a different carb and everything but I really liked it. Bike ran great, I even put that on after I had one of the old model lectrons on there and the jd kit felt much better. For under $100 it’s worth a try I’d say. Easy to follow directions and takes like 5 minutes to set up. I can’t see it making it worse.
queen of spodes wrote:
The bike I bought felt super rich on the bottom, almost blubbery like an old 500 2 stroke. I'd read so many positive reviews of the...
The bike I bought felt super rich on the bottom, almost blubbery like an old 500 2 stroke. I'd read so many positive reviews of the JD kit I figured it would be worth a go.

Like the idea of better mileage with the Lectron but worry I'd be in the same fiddly jetting mess as a standard carb.
Ive had three TC250's and tried all kinds of carbs and jetting. Had a JD jet kit in my 2017 and 2021 TC's. It worked great and the bike ran smooth all through the power.

In my new 2021 TC I swapped to a screw top Keihin 38 Air Striker. The bike has a little bit more bottom and more mid. Seems to be more responsive when cracking open the throttle. Its still not as responsive as my YZ and RM 250's but its close and I prefer it over the Mikuni. If you go the Keihin route, you have two options; Short body and screw top Keihin.

Screw Top: The 2017 will require a KTM intake from a PDS bike to make room for the longer carb: 554.30.250.100
**JD has a jet kit specific to this carb

Short Body: You'll need to bypass the Power Jet (not sure what that involves)
**JD has a jet kit specific to this carb

I've also had a Lectron on my 2017. Although the jetting was clean and crisp and pretty much spot on all the time (I'm at sea level) I felt it smoothed the power out too much. I like a harder hit. Throttle response was great but just didn't have that bark.
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mikie44
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mikie44 11/25/2021 7:57am
11/25/2021 7:57am
One more thing.. MOST importantly.... Play with the power valve adjuster! I run the adjuster FLUSH on my bikes.

The power valve setting makes a greater difference than any pipe (Yes, the PC pipes help over rev) but the power valve adjustment is free to adjust and makes a world of difference.
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dirtywardog 11/25/2021 8:20am
11/25/2021 8:20am
I've got a 100hrs on my 2017 sx250, stiffer spring in the back helped alot. PC pipe helps a ton, stock reeds still the best upgrade was a carb from a 2016 sx125 the muckygoome is a blubbery finikey carb once i've slapped the kehien in with stock jetting specs from a 2003 sx250 its been perfect. Bike is now at 100hrs and is holding up ok but the suspension is getting clapped along with it needed a top end, chain sprockets etc
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AJ565
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AJ565 11/25/2021 8:27am
11/25/2021 8:27am
AJ565 wrote:
Cancel the JD jet kit. It’s garbage.
queen of spodes wrote:
The internet is an interesting place. Googling shows a ton of positive feedback on the kit, then other folks say don't do it. Anyone have details...
The internet is an interesting place. Googling shows a ton of positive feedback on the kit, then other folks say don't do it.

Anyone have details on why the JD kit is either worthy or trash?
I too wasted money on it when I bought my bike. Was it better then stock? Yes. Did it run anywhere near or as clean as a 250 should? Not even close.

The correct jetting in the bike you’ll have better bottom end all the way to more over rev then stock and no sploog out of the silencer. I think you’ll be around $130-$140 in parts so not a lot more than the JD kit, but a lot better performing engine all around.
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dirtywardog 11/25/2021 8:51am
11/25/2021 8:51am
instead of spending 130 for jets, then anther 200 for reeds just buy a kehien carb and be done with it.
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queen of spodes 11/25/2021 9:02am
11/25/2021 9:02am Edited Date/Time 11/25/2021 9:03am
Here's the bike running. I had it on just to run the last bit of fuel out of the carb before storage. I don't know the current jet specs right now, did not have time to pull off the carb today.

https://youtu.be/_B3NWXEDGkE

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Markee
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Markee 11/25/2021 9:27am
11/25/2021 9:27am
AJ is the man with the jetting plan.

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