125-200cc 09 Wr 125 Bog/Performance Solved?

So David are you running the 144 now?

Not yet. I'm waiting to hear from Walt. I expect it to be another week or so. I presently have 7.0 hours on a new standard size ring in the 125 and I have gone to the #5 slide with the RM needle as per dartyppyt's instructions and the bike is pulling nicely. However, a little more grunt down low and in the middle would mean a lot to me in the tight stuff that I ride most of the time.

I also think a lot of our bog problems is coming from too high a float setting. I have lowered mine 3 times so far. Each time the bike runs better and gets even better fuel economy. The NOZH needle in the #3 position is working pretty well. I got about 20 mpg today at a H/S in deep sand. Sadly I got 3rd behind 2 450 Husabergs. Caught one and passed him on last lap only to have him shave a turn to get in front within a 1/2 mile of the finish. The other rider I didn't even know he was there or when he passed me and the other Berg rider.

Dwight, what height are you now running your float.
To lower your float do you add a mm or so?
Keihin recommends 16mm as standard for all 35-39mm PWK.

I haven't a clue on what it is now set to or even how to correctly measure the float level on this carb. But, I realized that my carbs were overflowing very easily and I kept lowering till it quit and then went a tad more.

Year & Bike Model = 2011 WR150

Carb = 36mm Keihin PWK A/S from 2011 KTM 150XC

Pipe & Silencer = Stock pipe or FMF pipe & FMF S/A silencer

Other engine mods = Exhaust springs Stock / silver.

Premix ratio & fuel type = Maxima Super M 40:1 or K2 , 100LL AvGas / 110 Sunoco race gas mixed 4 gal AvGas to1 gal Race Gas. Non Ethanol Gas is very hard to find in Mississippi and may not be anywhere according to the Gas Distributor.

Temperature range (deg F) = 65 -105

Elevation (feet) = 300ft. - 1700ft ASL

Main jet = 175 (stock 170)

Pilot jet = 35

Needle = NOZH (stock NOZI) So I can run the needle deeper into the needle jet. NOZ_ needles are short.

Clip position = #3

Air screw setting = 2 1/2 (stock 1 3/4) Slide = 6.0 (stock 7.0)

Wow, after months of riding with a flat spot in the middle, I finally had the time to go back over everything and I believe I originally did not have enough pre-load on the PV arm. I re-adjusted the arm and BINGO got it to pull in the middle. My bike has real smooth power from bottom to top now with no suprise rush (kinda boring) but it's great for the stuff I ride in! As noted in my current set-up below I'm running a small pilot, I may even need a smaller pilot in the summer as it has no bog off idle even when cold!?. My set-up:
2009 WR125 with power-up kit, FMF gnarly pipe and spark arrestor, stock PV spring/silver combo, AMSOIL Dominator 40:1 w/ 93 octane pump gas 60-70 degrees, 600-800 ft elevation (central NC)
Stock Mikuni Carb with 5.0 slide, RM 62 needle in middle pos, 450 Main, 30 pilot, Air screw 2 turns out

Sounds good! If you have time, send it off to RB and have the low circuit mod/divider put in it, front only. That will make even another noticeable difference on the bottom/throttle response. Try going up to 460 or 470 to see if you can get some more mid/top end?

Awesome help-I'll have to look up about the low circuit mod as I haven't seen anything on that yet...thanks!

Philbilly, good input, thanks... which 62 needle are you running, 17-62 or 16-62? got a pic of where you adjusted the PV arm? pretty sure mine is perfect, just curious.

i've been slowly leaning out my 144, almost dropped the pilot to a 30 this past weekend (current down to 32.5 from 35) but wasn't sure how low the temps would get. i'm still getting a lot of spooge. i let some friends ride the bike at a sand track, one of them an AM MX racer, the bike was smoking in the high revs. seems i def need to lean things out across the board.

4 non-Husky guys rode the 144 and all came back with huge smiles the fast guy definitely noticed the bog when you shift on the pipe. i'm determined to make this thing crisp everywhere. it's close but not perfect yet.

I am running the 62 needle and I just ordered a 27.5 and 25 pilot to try. I wouldn't go by any pic on how the PV arm is adjusted (that's what I did the first time) and I'm guessing the PV was not closing "snug" when at slower rpms. I re-checked my PV "pre-load" by moving the arm up (opening the PV) and letting it down slow until the arm stopped on its own, then, when I pushed down it, it moved a tiny bit further down (I believe you don't want any further movement-even a very tiny bit like mine did). In other words, you have to adjust the arm up enough with the adjustment nuts so there is plenty of spring tension holding the PV completely seated in the closed position. Use the picture for a general guide but open and close the PV by hand (slowly) to check how well it closes on its own. If it does not close fully, adjust the arm up a little more so it does. Good luck!

thanks, Philbilly. i'll try that and see what happens.

It was the same with the old TMX carbs.

i think mine are set at 18mm.

i have a wr125 with a cr125 engine running a old flat slide tmx 38.initially bogged just before pv opened, adjusted pv to max spring tension ..still bogged.did a spark plug read and changed jetting and ground the cut out on the no.4 slide, fitted a home made carby divider to reed side of carb and changed lower petals to low position and reset float level and advanced ignition slightly.i run no base gasket and have a compression of 190psi.jetting is 25 pilot and 370 main needle 60 mid position elevation is around 500 ft temps 15 to 40 degrees centigrade.runs great only time i have a foul issue is on some of the boulder hills where you can be minutes luggin around and pushin and clutchin the bike to get through but i don't want to go any lower on the pilot.the wr engine that came with the bike is a 2007 model the cr is a 2002 model the casting and matching seems to be better on the old cr motor maybe this is one of the reasons all the engines seem to behave differently with jetting set up.i used permatex ultra copper as a base gasket with no issues, this little engine never seems to get overly hot even when screamin around in 30 degree heat.

My Keihin PWK A/S 36mm is now set at about 12mm. I bet I could set it lower still. I thought the TMXX was about 8mm ? Maybe someone else could say what they are running their Mikuni float level at.

I have two ,01's and an 04, 125s and all 3 require different jetting.

Spec float level for the Mik TMXX is 6mm + or - .5mm. I've got both my bikes set at 7.5mm and get no bowl starvation at prolonged WOT and only get spillage when I go beyond 45 degrees tipover.

One interesting thing worth mentioning: My 2011 CR 150 had different float heights left side to right side. I noticed that the metal mounting bracket that connects both floats together had a slight bend downward on the right side (looking down at the floats with the valve pin farther away from my face). I bent the bracket till both floats measured equal. This seemed to solve a weird idle starvation issue associated with leaning the bike to the right.