I own a 2017 KTM 250SXF, Prior to this bike i had a 2008 YZ250F that i used on and off the last few years before purchasing my KTM in 2017.
Like all bikes KTM has there little things as well. When you but a new bike they come with a owner/service manual. Read these. Do not be afraid of maintaining you bike. After all you probably just spent $8699.00 on your new 250f. KTM will tell you straight out of the gate things to keep a eye on. Spokes are and have been since 2014 a issue on these bikes. Mainly the rear rim lock location. Rear sprocket bolts even on the 19 are still coming loose the first few rides. All that power to the rear will has to go somewhere and yes its not all applied to the ground.
I had a starter issue after my second ride. Bike would not turn over. I took it back to the dealer pretty pissed but learned the nut over the wire came loose from manufacture. Another thing KTM suggest you look at to make sure it is tight. Im coming up on two years with this bike and i have never seen this issue again.
Front steering nut - If your bike is on a stand and the bars constantly fall to a side extremely easy then its time to adjust this. If your a re skilled enough rider to understand what is happening to a bike while riding it you will have noticed the bike seems rather twitchy in higher speeds. These will loosen again after even the first ride. This is not a flaw it is perfectly normal these do that. If this bolt is to tight you just wont turn its pretty simple. The manual explains this perfectly. Loosen your top triple clamps then remove the nut that is horizontal to the steering nut. Torque the steering nut to 12 Nm or 8.9 ft lbs. Then set that screw that was horizontal to your steering nut back to place in the torque specs i believe its 20 Nm or 14.8 ft lbs then tighten your top triple clamps again. Follow torque guidelines.
Oil service - (seems to be a lot of fear here due to how KTM wants it done and if it is done incorrect you could damage a engine)
Dont worry follow the manual it is rather easy. I changed oil in between 5-7.5 hours on first oil, after shavings are gone from oil and filter this will be a longer life of oil between service. Get the bike hot. Drain oil, There are two oil filter systems. The main one we all know and another right under the counter sprocket that is a thin mesh screen filter. Before filling oil back up pull this filter and clean with brake or carb clean. You will eventually have to replace this refer to owner/service manual. Follow the service manual on how much goes into the bike.
When filling oil back up lay bike down on the right side the the oil filter is looking up. set your filter in and fill oil filter housing almost 1/2 full. check service manual for exact. Close oil filter housing then get bike back to its wheels. Fill remaining oil into engine oil filler location. Usually takes 1.1 QT in total between engine and oil housing. This should fill bike to half in the site glass. NOTE: when bike is actually running this level will most likely drop right at the bottom of the circle do not panic and fill more you can seriously damage engines with to much oil. This creates enormous pressure causing seals to blow out.
Frame bolts - The frame flexer that have 3 star bolts will come loose keep a eye on these. These steel frames flex unlike a aluminum frame. This is normal but most of your are young and probably grew up in the aluminium phase. My 1997 KX60 did this stuff to and my Yamaha 85 and Kawasaki 85.
Tighten your chain - 3 finger rule. Here is the good news. KTM is not cheap so you can actually ride the stock chain on these bikes without having slip through your case - (Most common on all Japanese bikes....) For real though if you own a Yamaha, Honda, Kawasaki or Suzuki change that chain right away. They even will tell you this at the dealer as well as all the other shit flaws on them and trust me they have a ton.
Fork seals on the WP AER 48 - Simple instructions. Clean your dam bike. the most common tear to seals is laziness. the hard dry dirt will cut this if you do not wash your bike after every ride day. Also invest in a seal savor that mounts under your fender and between your tire so when you tie down it keeps the fork from compressing to far. Also dont be the guy that leaves your bike tied down in the truck or trailer all the time. That is just stupid.
Like i said these are normal to all manufactures. They all have their things that need addressed. If your looking to buy a bike and not maintain it then shame on you when they fall apart. You cant buy a bike and do nothing to it. Over time you will have yourself a rats nest if you do not follow the service guide.
For the record KTM does not suck. I have been so pleased with the bike that i feel my money was well spent. Remember i cam from Yamaha so the best turning, suspension all around bike on the market and i feel i made a upgrade.