KTM 790 Duke (2018-2020) Maintenance Schedule and Service Intervals
This is the maintenance schedule and service intervals for the KTM 790 Duke, which KTM branded “The Scalpel”.
The KTM 790 Duke is based on an all-new LC8c (the “c” being for “compact) engine, which was adopted into the KTM 790 Adventure the following model year.
It’s a liquid-cooled fuel-injected 799cc parallel twin that in the 790 Duke makes max power of 78 kW (105 hp) @ 8500 rpm, and 86 Nm (64 ft-lb) of torque at 8000 rpm. Quite a capable and fun motor!
The final drive is via a PASC anti-hop clutch and chain drive.
After a brief stint, the KTM 790 Duke was replaced by the 2021 KTM 890 Duke.
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What you need to service your KTM 790 Duke
Apart from basic motorcycle maintenance tools, here are a few spares, fluids, and consumables that will help you service your KTM 790 Duke.
| Part | KTM 790 Duke spec |
|---|---|
| Engine oil | The manual for the 790 Duke specifies Motorex Power Synthetic 4T 10W/50, or another SAE 10W/50 fully synthetic engine oil that meets JASO T903 MA2 spec. |
| Oil filter | Use part number 61338015200 or K&N part KN-650, a popular equivalent. (This oil filter is used in most modern KTM street/adventure bikes.) |
| Fork oil | The manual recommends SAE 4 fork oil, ideally Motorex 4W fork oil. |
| Brake fluid | The manual requires DOT 4 or DOT 5.1, recommending Castrol DOT 4 or Motorex DOT 5.1 brake fluid. |
| Coolant | KTM recommends Motorex Coolant M3.0 or other “high-grade, silicate-free coolant with corrosion inhibitors”. |
| Spark plug | Use an NGK LMAR9AI-10 to change spark plugs. |
| Chain maintenance | KTM recommends using Motorex chain cleaner and Motorex chain lube. But a Motul chain care kit is a popular option. |
Maintenance Schedule for the KTM 790 Duke
Below is the maintenance schedule for the KTM 790 Duke, adapted from the manual.
Notes:
- Maintenance schedule intervals for the KTM 790 Duke are every 15000 km (9300 mi), with a major service (valve service & new plugs) every two service intervals.
- After the end of the service schedule, keep repeating it like this — service every 15000 km, alternating between major and minor intervals.
- The maintenance schedule in the manual is broken up into two sections — required maintenance and recommended maintenance (but you should do both).
Required maintenance
| miles x 1000 | 9.3 | 18.6 | |
|---|---|---|---|
| km x 1000 | 15 | 30 | Every |
| [Dealer] Read out the fault memory using the KTM diagnostics tool. | ✓ | ✓ | Year |
| [Dealer] Program the shift shaft sensor. | ✓ | ✓ | Year |
| Check that the electrical system is functioning properly. | ✓ | ✓ | Year |
| Change the engine oil and the oil filter, clean the oil screens. | ✓ | ✓ | Year |
| Check the front brake linings. | ✓ | ✓ | Year |
| Check the rear brake linings. | ✓ | ✓ | Year |
| Check the brake discs. | ✓ | ✓ | Year |
| Check the brake lines for damage and leakage. | ✓ | ✓ | Year |
| Check the front brake fluid level. | ✓ | ✓ | Year |
| Check the rear brake fluid level. | ✓ | ✓ | Year |
| Change the front brake fluid. | 2 years | ||
| Change the rear brake fluid. | 2 years | ||
| Check the free travel of the clutch lever | ✓ | ✓ | Year |
| Check the free travel of the foot brake lever | ✓ | ✓ | Year |
| Check the shock absorber and fork for leaks. Perform fork service as needed and depending on how the vehicle is used. | ✓ | ✓ | Year |
| Clean the dust boots of the fork legs. | ✓ | ✓ | |
| Check the steering head bearing for play. | ✓ | ✓ | Year |
| Check the tire condition | ✓ | ✓ | Year |
| Check tire pressure | ✓ | ✓ | Year |
| Check the chain, rear sprocket, engine sprocket, and chain guide. | ✓ | ✓ | Year |
| Check the chain tension | ✓ | ✓ | Year |
| Change the spark plugs | ✓ | ||
| Check the valve clearance | ✓ | ||
| Check the antifreeze and coolant level. | ✓ | ✓ | Year |
| Check the cables for damage and routing without kinks | ✓ | ✓ | Year |
| Change the air filter, clean the air filter box. | ✓ | ✓ | |
| Check the fuel pressure and the absorbing elements of the fuel tank bracket. | ✓ | ✓ | Year |
| Check the headlight setting. | ✓ | ✓ | |
| Check that the radiator fan is functioning properly. | ✓ | ✓ | Year |
| Final check: Check the vehicle is roadworthy and take a test ride. | ✓ | ✓ | Year |
| [Dealer] Read out the error memory after the test ride using the KTM diagnostics tool. | ✓ | ✓ | Year |
| [Dealer] Set the service interval display. | ✓ | ✓ | Year |
| [Dealer] Make a service entry in KTMDealer.net | ✓ | ✓ | Year |
Recommended maintenance
| miles x 1000 | 9.3 | 18.6 | |
|---|---|---|---|
| km x 1000 | 15 | 30 | Every |
| Check the frame | ✓ | ||
| Check the link fork | ✓ | ||
| Check/clean the oil nozzle for clutch lubrication | ✓ | ✓ | |
| Check the fork bearing for play | ✓ | ✓ | |
| Check the wheel bearing for play | ✓ | ✓ | |
| Empty the drainage hoses | ✓ | ✓ | Year |
| Check all hoses (fuel, coolant, bleeder, drainage etc.) and sleeves for cracking, leaks, and incorrect routing | ✓ | ✓ | Year |
| Grease all moving parts (e.g. side stand, hand lever, chain) and check for smooth operation | ✓ | ✓ | Year |
| Check the tightness of the safety-relevant screws and nuts which are easily accessible. | ✓ | ✓ | Year |
| Change the coolant | 4 years |
Wheels and Tyres for the KTM 790 Duke
The KTM 790 Duke ships stock with Maxxis Supermaxx ST (sport touring) tyres, but you can use any kind of tyre you find appropriate, as long as they meet the same speed rating.
| Wheel | Tyre size | Tyre pressure (cold) |
|---|---|---|
| Front | 120/70 ZR 17 M/C 58W TJ (J) | 33 psi (2.3 bar) |
| Back | 180/55 ZR 17 M/C (73W) TL (G) | 39 psi (2.6 bar) |
About the KTM 790 Duke
The KTM 790 Duke was a huge step forward from its predecessor, the KTM 690 Duke. In one major way — the 790 Duke has a parallel twin engine! The 690 Duke only had a single-cylinder engine.
And it’s a cracking engine. The 790 Duke’s engine is a 799 cc liquid-cooled parallel twin with a 270-degree firing order (bang-2-3-bang-5-6-7-8), like the motor in the Yamaha MT-07. The engine revs freely and quickly, spinning up to 10,000 rpm, but making its peak of 78 kW (105 hp) at 9000 rpm, and peak torque 1000 rpm earlier at a peak of 87 Nm (63 ft-lb).
It’s a “modest” middeweight amount of power, but then you see that the KTM 790 Duke weighs only 188 kg wet (on Cycle World’s scales). Coupled with its quick gearing, the 790 Duke is a lively and engaging ride — if the above (press pack) photos are any indication.
The KTM 790 Duke is let down only by having simpler (non-adjustable) forks than the up-spec R model in the 890 class (the KTM 890 Duke R). Many owners spent their own money upgrading the suspension, but then they missed out on the larger capacity engine of the 890 Duke which was released just two years after the 790.
That said, the KTM 790 Duke’s forks are cartridge-style upside-down forks. And you get preload adjustment on the WP shock at the rear at least.
KTM 790 Duke is a little brother to the fire-breathing SDR (the Super Duke 1290 R). It has the same spirit — a revvy, character-rich engine, racey geometry (without being a full-on sportbike), and aggressive styling. This is as sporty as a standard or naked bike can get.
The KTM 790 Duke, despite being a non-R, has a lot of rider technology. ABS is almost a given, but the 790 Duke also has a full IMU, meaning it has cornering traction control and ABS. Plus you can switch it into “Supermoto” mode, which means you can act silly without too much intervention.
Manual for the KTM 790 Duke
The above maintenance schedule comes from the user’s manual for the KTM 790 Duke.
You can get the user manual directly from KTM’s website.
