2021 KTM 790 Adventure R engine problems
11 owner complaints filed with NHTSA name the engine on the 2021 KTM 790 Adventure R — 50% of all complaints for this model year.
What owners report
“The valve train of my bike failed and left me stranded in the woods. There were no signs or warnings beforehand. After further research online, I found that this issue has been happening quite a bit. Luckily it happened to me while my bike was parked. The issue is the valve train is wearing out…”
filed Aug 6, 2025
“I have checked the cam shafts condition at only 3900 miles since there are a lot of people with the same motorcycle mentioning this issue and there is an unsuspected wear starting to happen. Motorcycle always ran on recommended Motorex oil and air filter was maintained as it should be.”
filed Apr 4, 2024
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Other reported problem areas on the 2021 KTM 790 Adventure R
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.