Jetting App

I use the Yamaha jetting app from the app store on my iphone. Seems to get me really close. Has settings for temperature, humidity %, elevation, etc. 

I've always used the JD Jetting kits on every carb'd bike and followed their recommended settings and never looked back. Never had any issues.

Just picked up a 2023 GasGas 85 for the kid.  According to the manual, the carb is jetted for roughly 70F and around 1200ft of elevation (give or take a few hundred feet).  After his first ride this weekend, noticed it seemed a little "fat" off the bottom and had a good bit of "drool" out of the exhaust.  We were at roughly 500ft elevation and upper 70's on temps.  I haven't pulled the carb yet to check the jets and make sure they are what is listed in the manual, but I will soon.   It definitely needs a smaller pilot (or idle jet) and probably some other adjustments as well.  This was at a 40:1 mix.

I am on an android phone, but there is a KTM jetting app in the store that covers this model.  It is $5.49/year.  It looks pretty good, but I have not paid for the full service to see what it recommends. Once I have a chance to verify the actual settings in the carb, I will start making adjustments.  Will be curious to see if anyone else has any apps they recommend and how that compares to what we actually wind up running.

I just spent the $5.49 on the Yamaha 2T app. It's recommending a 10 heat range plug for the 2022 YZ125... I've never heard that recommended for a 125 before. 

Didn't know jetting apps existed, but make sense. Thanks for the tip

The Austrian 85's are very easy to jet.  The stock jetting is not far off and the Keihin PWK on the bike is very responsive and "logical" to changes.

Step-1, move the clip from 3 to 2.   This should be done about 5 minutes after you buy the bike.  This is the main cause of your drool.

After that, it's really just fine tuning per conditions and fuel.  But you should not get very far off from stock.  Stock needle is NRKC.  I think the spares kit includes an NRJC also.  If not, get it.  It is 1/2 clip leaner and can be used to really fine tune the bike.   I never went leaner than 45 on pilot and never above the stock 48.  Main, stock is 142 and I never went farther than 140 or 145.  This was after 3 solid years on about 5 different bikes everywhere from 35 - 105 degrees and 500 - 5,000ft.

Thanks for the info FGR01.  My initial thoughts were to drop the pilot 1 size, move the needle down 1 and *maybe* go down 1 size on the main.. only because summer is coming and it will be in the 90's here most of the time.  I'll wait on the main until we have a little more time on it.  There was a small selection of jets and an optional needle that came with the bike, although I have yet to look at them closely. 

Also, I am running AV gas.  It's easy for me to get.

I ran Avgas in all these 85's.  Very easy to jet for in those bikes.    I agree with your thinking that you'll generally need to lean out.  I used to live in GA and know that heat and humidity.  The 2 put together can richen a bike right up.  If you're running Avgas, try NRJC on clip-2 when it's hot and humid.  

I use the KTM jetting app all the time. It’s a good reference point especially if you are traveling somewhere/different weather conditions.

it’s not perfect, but it’s pretty dang close and your personal tuning still comes into play 

Man, this FGR dude sounds like he knows what goes where, why.

How's it going, buddy?

I wish they had these apps when the kid was on a super-mini.

Probably wouldn't have helped considering how jacked the engine was. But damn, I was always working on the carb on that thing. 

He was a shitty tester too. "It's fine, Dad".

Spooging, plug looks like crap... whatever. 

Going!  Getting hot over there yet?

https://www.youtube.com/watch?v=dppHVv1HHVY&t=5s

Not an 85 guy but this guy says install the optional NRJC needle then run what's in the manual but goes down one size on the pilot.

The taper of needle changes the fuel delivery like you can't do with just swapping jets. On 250's lots of guys switch to a NEDJ needle and it really cleans up the first 1/4 throttle, helps it rev quicker.

I've got the Suzuki jetting app.

For my 08 RM250 its pretty darn close. I'm 1 step leaner on main and using an NEDH and not the NEDJ on the app. It's handy for extremes of weather and helps save a bit of guessing when going between the peaks of summer and winter

The only things that's really off is it recommends a BR9 plug which is not correct for the bike. So ignore the plug recommendation from the app and stick with the OEM plug stated in the owners manual