AI Damage2021 KTM 790 Adventure R: common problems
Owners of the 2021 KTM 790 Adventure R filed 22 complaints with NHTSA, most often about engine and fuel/propulsion system. Details by component below, with sources.
Key figures
- Owner complaints
- 22
- involving a crash
- 1
What fails most often
- 1 Engine 50% of all complaints
- 2 Fuel/propulsion system 36% of all complaints
- 3 Service brakes 23% of all complaints
- 4 Exterior lighting 18% of all complaints
- 5 Electrical system 9% of all complaints
- 6 Powertrain 9% of all complaints
- 7 Tires 5% of all complaints
- 8 Vehicle speed control 5% of all complaints
- Engine: 11 complaints (50% of all), 1 of them with a crash reported by the owner.
- Fuel/propulsion system: 8 complaints (36% of all).
- Service brakes: 5 complaints (23% of all).
- Exterior lighting: 4 complaints (18% of all).
- Electrical system: 2 complaints (9% of all).
Symptoms owners describe
How many of the 22 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Engine | 11 | 1 | 0 |
| Fuel/propulsion system | 8 | 0 | 0 |
| Service brakes | 5 | 0 | 0 |
| Exterior lighting | 4 | 0 | 0 |
| Electrical system | 2 | 0 | 0 |
| Powertrain | 2 | 0 | 0 |
| Tires | 1 | 0 | 0 |
| Vehicle speed control | 1 | 0 | 0 |
| Other | 3 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
I recently discovered that the brake light does not activate when applying the front brake lever. I became aware of the issue only after noticing that the motorcycleâs cruise control system would no longer engage.
A bike suddenly stalling out in traffic isn't the safest scenario for a motorcycle rider. Especially if they're riding at interstate speeds. If you search online, you'll see others with this issue and it's much worse than mine. There are numerous YouTube videos and even a dedicated Facebook page about this issue.
I have had three separate incidences of the either the front or rear brake sensor switch failing which requires replacement. It causes the brake light to not function. I do have one of the three switches for inspection. It has been confirmed by a mechanic.
Good day to whoever is reading! I've recently discovered that my brake light does not turn on on my bike no matter what brake i use front or rear. Only way it works if i push brake really hard, like way beyond regular or emergency braking. I've found similar issues online and people pointing on faulty brake sensors.
Will stall out and need to attempt to restart it several times before it will run. Appears to be running on a single cylinder for 30-45 seconds when it does finally start up then will run as normal. This does not occur when the motorcycle is already warm.
Tire size 90/90-21 front tire inflated with Motorcycle manufacturers recommended psi without warning it instantly deflats. I had this happen twice with the same tire. Once deflated it causes the tire to debead off the rim while riding and renders the motorcycle nearly uncontrollable.
1) The vehicle TFT display containing important data such as speed etc.. blacks out on occasion. The vehicle itself is still functional but with the display blacked out the operator has no speed information, or information about the vehicle such as fuel levels and ABS control.
Motorcycle stalled at intersection of busy highway, would not start creating hazard of being hit in the intersection and while pushing it to side of road. Mechanic inspected vehicle, found excessive wear to valvetrain causing engine power loss and stalls.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 7,906 of 36,659 model years in the NHTSA data (top 22% most complained about).
On average one model year of the 790 Adventure R has 10 complaints (5 years in the data). This year has 22, above average.
What to check before buying
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Fuel/propulsion system. Fuel smell, leaks, rough running, fuel-system codes.
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Exterior lighting. Headlamps, leveling, sensors and mounts after a frontal hit.
Other years of this model
Questions and answers
What are the most common problems with the 2021 KTM 790 Adventure R?
Owner complaints to NHTSA most often mention: engine, fuel/propulsion system, service brakes. Total complaints: 22. The most frequent symptoms in complaint texts: stalls while driving (23%), won't start (14%), loss of power / limp mode (9%).
How many service bulletins (TSB) were issued for the 2021 KTM 790 Adventure R?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2021 KTM 790 Adventure R from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2021 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-06.