125-200cc Going from 125 to 144 - Jetting?

I have stock jetting in the Mikuni TMX 38. I'm usually about 1500 feet 70 degrees (F) 50% humidity in Western PA. The 125 jetting as of now is: Pilot seems rich (stutters), Main seems lean (bogging). I didn't bother changing it because I knew I'd be going to 144 soon.

Do you typically need to go leaner or richer when going from 125 jetting to 144 jetting?

I have a 2008 CR 125 the stock carb and all stock setting Raced it for a few years as a 125 and never touched the stock carb settings. Then I went 165 and again raced it now for 2 years,the carb is still stock as delivered from the factory with the original settings It ran fine as a 165 and I felt no need to change it
I have rode from below sea level to up around 8,000 from 26 degrees to up over 100 still no change
i do run stright race gas mixed around 35 to 1

I never rode mine as a 125, but after a bunch of tuning, I now have 30 pilot, 1 clip richer on the needle (this made a huge difference in midrange power) and stock 460 main. I may try a 450 and 470 main when I can get them. A 480 (all I could get) was too big, and killed the top end with the other settings I have now.

The pilot made it much crisper, with instant response on the bottom, and with the needle adjustment, i have a hard time keeping the front end on the ground on corner exit.

For MX it's excellent. I ran a 6 hr hare scramble on the weekend and had a small amount of spooge on the fender, but it ran strong everywhere. Pretty sure it's the needle, but for what I'm doing, the bike runs great and I'm not changing it.

Check the jetting database: http://www.cafehusky.com/threads/new-and-improved-2-stroke-jetting-database.27395/

I don't know about the little bikes as much, but on the 250/300s, the bigger motors use a slightly smaller jet.

Which needle are you on? The stock needle GAY has an odd taper, you might want to consider one of the other Husky needles (DEY?) or aftermarket (JD).

I don't want hijack your thread but i'm near you and i'm wondering what jetting are you running now? Mine had a 460 main, 32.5 pilot and 3rd clip on the needle and it was too rich down low. I lowered the needle 1 slot and put in a 25 pilot because it was what I had but it seems a little lean. Main seemed about right.

I've got some more jets ordered, should be here by the weekend.

Is it a 125 or 150?

I'm running the stock jetting right now, I have a 2012, but according to the 2011 manual that I have, the jetting is: 460 Main, 35 pilot, 3rd clip.

125 for now although it'll be a 165 in a few weeks

460 main seems right, I did a chop and the plug was a nice tan/brown.

Did you see the thread here about adjusting the power valve linkage? It may help with the bogging.

I did.

And PLEASE if you get the 165 - we need to meet up. I'm dieing to ride one!!

It's a bog that sounds like 'burbling'. I think it is lean. It's not really a 'i have no power, so I'm going to bog' bog. lol. but I am going to do adjust the PV

I agree 100% that it will never be perfect for both. I do think it could be a little better, but that would affect the way it runs on the motocross track.
I disagree about reading the plug. A plug reading is only good for one setting, and that's wide open. Anywhere else the plug reading can't tell you anything. That, and when you see a nice tan, or light brown plug, you've already gone too far.

Typically, these bikes come jetted a little rich on the main and the pilot to keep them from seizing when they are ridden WFO all day at seal level when new.

My 04's had to be leaned 1-2 steps on the main and 1 step on the pilot.

390 main in the sand and 380 main in the rocks...32.5 pilot everywhere.

Make sure the float level is correct....it makes a big difference in gas mielage too.

Sure thing. Have you considered a lectron? I'm very happy with mine. Once they are setup you probably won't need to touch it again. Literally the only thing I do is go a little richer on the power jet screw if I know I'm going to be running in a lot of mud.

I have, just don't have the cash for one at the moment! Haha. And by the way, I'll let you ride the 144 too if you've never ridden one. I am installing it this weekend