Spot-on jetting for your 2-stroke Yamaha YZ, the nearest weather station in one tap, and a logbook that learns how your bike runs. 10 models, 1995 to 2027.
This app helps you jet your 2-stroke Yamaha YZ (PW 50, PW 80, YZ 65, YZ 80, YZ 85, YZ 85 LW, YZ 125, YZ 125 X, YZ 250, YZ 250 X) and get the most out of it. From the temperature, altitude, humidity, atmospheric pressure and the oil-to-fuel ratio it works out the jetting recommended for your exact model.
To get the weather values the app can use the location service and the data connection: it takes your position and altitude, queries the nearest public weather station and brings back its readings. It also works with no GPS and no data, entering the weather by hand.
The app has 4 tabs:
- Results: the recommended main jet, needle type and clip position, pilot jet and air screw turns for the conditions and the bike you set, plus air density and density altitude. It has fine tuning per circuit —high, mid and low— to match the character of one particular engine.
- Conditions: temperature, altitude, pressure and humidity. Type them in, or pull them from the nearest weather station with one tap, without leaving the screen.
- Engine: year, region, model and oil mix ratio. The carburettor is not a choice: the year, region and model determine it.
- Logbook: saves each ride with the bike, the weather and what the app recommended, so you can note afterwards what you actually fitted and how it went, rated per circuit. Export it to CSV or share a copy to move it to another phone; importing never deletes anything.
Units: metres and feet for altitude, ºC and ºF for temperature, mb, hPa, mmHg and inHg for pressure, and kg/m³, lb/ft³ and lb/gal for air density.
No ads, no tracking and no account.
Yamaha YZ models that are included:
- PW50 from 1995 to 2027.
- PW80 from 1995 to 2024.
- YZ65 from 2018 to 2027.
- YZ80 from 1995 to 2001.
- YZ85 from 2002 to 2027.
- YZ85LW from 2022 to 2027.
- YZ125 from 1995 to 2027.
- YZ125X from 2016 to 2027.
- YZ250 from 1995 to 2027.
- YZ250X from 2016 to 2027.
I tried this setup and it worked great! Some may say that it doesn't work because the bike won't idle, but they don't understand that this is how bikes are race tuned - it is to help the bike slow down faster with engine braking. If you have a doubt, adjust it first and grab the throttle halfway - it will lift the front end well before it hits the powerband. I went to sand mountain (Utah - 700 ft high dune) and the bike was still grabbing more power as I was flying up the dune in 3rd gear 1/2 to wide open throttle. Highly recommended.
Spot on…!!!
DC Equipment
I use this app for all my two strokes. I live in Reno Nevada and ride Nor Cal MX tracks often. The jetting recommendations is always spot on for me. More riding and less jet changes. 😎
Update Your App
Bishnu S.
This app is still suggesting the 2006 and older needle jet N3EJ as standard for just about all temps/ elevations for a newer YZ250 including warm climate close to sea level. Yamaha changed to the N3EW needle in 2007 as it improved bottom and mid range. I assumed I needed to go with the leaner N3EJ needle as per this apps suggestion so I purchased one. It is not an improvement. I did plug in 2017 as the year of my bike. Take some time and get everything correct and current for one of the most common 2 strokes available. The other settings seem accurate. Also not a huge deal but a nice touch would be to list the YZ250X as a selectable option. I get that the jetting is the same as a YZ250 but at least list it.
Ok setting suggestions
allthenicknamesaretaken$&$$
But the pilot jet recommendations are far off, ie 5000 to 10,000 asl only recommends a turn out on a/s when I’ve found 2 sizes down on pilot is necessary, seems to recommend rich settings here. It’s difficult to input elevation with the keyboard being in the way.
Developer Response
Hello, the issue with the elevation input is solved since last update.In the case of the pilot jet recommendation, our model tries to enrich at low in order to be safe (most seizes are after WOT and suddenly close throttle), and that let us put a one size leaner main jet to maximize power.
Logbook, and the weather station now inside Conditions.
- New Logbook tab: it saves each ride with the bike, the weather and what the app recommended, so you can note afterwards what you actually fitted and how it went. Rating goes per circuit: low, mid and high.
- Export the logbook to CSV, or share a copy to move it to another phone. Importing never deletes anything: what is missing gets added and what is there gets updated.
- The GPS tab is gone: the nearest weather station is now queried from Conditions, which is where the readings end up anyway.
- New launch screen, result boxes that use the full width of the screen, and values that no longer get clipped.
- Help rewritten from scratch, one text per screen, in all seven languages.
And from version 2.4, in case you skipped it:
- Bikes updated through 2027, with the YZ85LW as a new model.
- Jetting reviewed against the official Yamaha service manuals.
- More accurate response to altitude.
This version requires iOS 15 or later.
Version 2.5
The developer, ISEnet, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Ingenieria del Software ISEnet S.L.
Size
2.5 MB
Category
Sports
Compatibility
Requires iOS 15.0 or later.
iPhone Requires iOS 15.0 or later.
iPad Requires iPadOS 15.0 or later.
iPod touch Requires iOS 15.0 or later.
Mac Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
