KTM - Essential Basic Settings
We can't overstate how important these base adjustments are for your bike to start, idle, and run correctly.
This is written for the KTM dirt bike line, but the same basic principles apply to all bikes.
Low idle symptoms
Hard starting
Engine is hard to start cold or hot.
Flame out
Engine stutter stalls in low speed technical riding.
Cough and stall
Coughs, then dies. Often right when you need it not to.
Stalls on decel
Closes the throttle coming into a corner and quits.
Idle speed spec
With the engine up to operating temperature, use a test instrument to set the idle speed to factory specifications.
| Model family | Target idle |
|---|---|
| 450 / 500 / 501 EXC-F, XCF-W, FE, FEs | 1800 to 1900 rpm |
| 250 / 350 EXC-F, XCF-W, FE, FEs | 1950 to 2050 rpm |
| 250 / 350 / 450 SXF, XCF, SM | 2250 to 2350 rpm |
Find your idle knob
2012 to 2016 enduro
2011 to 2015 MX
Idle speed and choke are both handled by a single round black knob on the left hand side of the throttle body.
2017+ enduro
2016+ MX
Red knob sets idle speed. Yellow knob handles fast idle, which is the choke.
Measure it, don't guess
Almost all cold starting and stalling issues are idle speed related, and it's essential to set your speed to spec. Use a calibrated test instrument. Guessing on the idle speed or doing it by ear isn't sufficient, especially if your bike has starting or stalling issues.
| Tier | Tool | How it reads rpm |
|---|---|---|
| Low cost | Tusk Tach / Hour Meter | Pickup wire wraps around the ignition coil wire |
| Low cost | Hardline HR-8061-2 Hour / Tach Meter | Inductive one wire pickup, no splicing into the harness |
| Mid cost | Trail Tech Vapor gauge | Full wired dash with tach, temp, speed, and hours |
| High cost | Trail Tech Voyager Pro kit | Wired GPS computer with tach, mapping, and logging |
| App | SoundTach | Reads rpm through your phone, nothing to install on the bike |
TPS calibration
We don't recommend adjusting or setting the TPS to anything besides factory spec. There's no hidden power in there, and the internet TPS hack isn't the fix people think it is.
Everything you ever wanted to know about it
Moto Myth Busters: the TPS hack and everything throttle body.
Cold starting procedure
Once TPS calibration is confirmed and idle speed is set correctly, this is how you cold start the bike.
- Fast blip the starter button to prime the fuel system. Do this at least once. Very cold days may take two times.
- Crank the bike by holding the starter button in for three or four seconds, then release.
- If the engine doesn't fire, pause for three to four seconds and crank again.
- Repeat until the engine is running. It's not unusual or unexpected to perform 2 to 3 crank cycles to start a single cylinder bike on a cold morning.
If it needs a little help
Some bikes in some cold start situations need a slight throttle crack to light off. You can get that by depressing the yellow knob on the bottom of the throttle body, or by slightly cracking the throttle and releasing it once the engine is running.
Working the yellow fast idle knob
Cold start engagement of the yellow fast idle choke knob will help. Push it in to engage, pull out to release.
You can also release it by turning the throttle grip forward and listening for the click. 20 to 30 seconds of idling with the knob engaged is typically all that's needed.
Go deeper
Still stalling after all this?
If your idle is set to spec and the bike still won't behave, something else is going on and we can help you chase it down.
Taco Moto Co. // support@tacomoto.co // 725-777-1552