Shinko 804/805 tires work really well on the 390 if you are not worried about getting super high mileage from them. We usually get about 4-5K miles from a set on our 390s. If you want more miles but don't mind a compromise in traction on sand/mud, the Dunlop Trailmax Missions will last 10K+ miles.
I would also highly recommend losing the OEM hand guards and replacing them with some Acerbis or something similar with the metal bar. The stockers are essentially worthless and break very easy, not even protecting the levers in the process.
Check your air filter frequently if you ride dirt often. For some reason, they get REALLY dirty really fast compared to other bikes I've had.
You may want to get new foot pegs if you have not already done so. The OEM pegs have a pretty good forward slant to them that makes them not real comfy for standing. We have these and like them,
Our pegs offer a wider platform for better control and grip over the factory pegs. Machined from 6061-T6 aluminum with an aggressive cleat design for better grip in all situations. Large openings in the foot peg keeps mud and debris from packing up in the peg.
rivalcomponents.com
But, I think you can find others that are likely just as good for a bit less $$.
Rox Risers really help as well when standing. However, if you install them, you will likely need to replace the clutch cable with a slightly longer cable. It is very easy to do and a new cable isn't expensive. Here are the risers and clutch cable we used,
Made in the USA 1 3/4" (44.5mm) Center-to-Center Rise Pivots Backward/Forward based on Rider Preference 26mm Stem Accepts 26mm Handlebar Always check and confirm that your machine has adequate cable and brake line length before installing handlebar risers! Clutch cable needs to be rerouted...
roxspeedfx.com
Motion Pro - High quality cables, tools and controls for motorcycles, ATVs, snowmobiles and personal watercraft.
www.motionpro.com
A cheaper option is to use block risers instead of pivoting risers. They are basically just spacers with longer bolts. They pull the bar up and back only. The benefit of the pivoting type is that they bring the bar up and let you change the forward/backward location of the bars a bit.
If you fall on the right side, be prepared to spend at least $100 on a new rear brake lever...
The OEM lever is cast aluminum and is prone to bending and/or snapping off completely. I am not sure if there are any aftermarket replacements yet.
The stock engine bash plate is not going to get it done if you ride anything other than mild dirt roads. Blackdog Adv bash plates are nice, but expensive. There are some others out there less expensive that will work. My son's 390 has the Blackdog because it was on there when we bought the bike. My daughter's 390 has the OEM plate and it already has some significant damage. I will probably be replacing it before much longer.
The kickstand safety switch on these bikes is VERY annoying. The kick stand can bounce if you hit a decent bump, causing a little magnet to lose contact with a relay and kill the engine unexpectedly. The solution is to just bypass the switch,
With the new era of over-complicated side stand sensors it is easy to be left stranded by a non-functioning safety device. Our product solves that inconvenience. Fitment: KTM 390/790/890 Adventure R/S - 2019-2023 Husqvarna Norden 901 - All Years KTM RC 390 - 2017-2021 Husqvarna Svartpilen 401 -...
vanaschemotorsports.com
If you want to mount a GPS. phone holder, or anything else right there behind the windscreen above the power outlet, these are great,
This product does NOT fit 2023 KTM 890's. See here for 2023 890 Mount This product does NOT fit the Norden 901. See here for Norden GPS Mount Hands down the most rigid setup that mounts directly to the 390/790/890 factory GPS location (believe us, we've tried them all)!! This is NOT a 3D printed...
vanaschemotorsports.com
There are other brands out there though.
Lastly, check these bikes over FREQUENTLY. Other than my old KLR 650, I have never seen bikes that shed bolts like these do. I don't know if it is because they don't loc-tite them from the factory or don't give them enough torque at the factory, but I have been ordering replacement bolts for these bikes right and left! The bolts themselves are not that expensive, but the shipping will kill you
Any bolt you remove while working on the bike should be loc-tited (blue at least) and properly torqued!
LOTS of people do the exhaust resonator removal, add a pipe, and something like the Fuel-X lite/pro tuning kits. We've not done any of that and really have no plans to. The bikes run fine for use and we haven't had any of the stalling or overheating problems some people complain about. If you want to see how the bikes handle a serious adventure trip, go
here.