All 2st Jetting Chat - Need Help? Post Your Questions Here

After an engine seizure, months ago, my "00 Husky WR250 is running quite bad.
Every week the Mikuni carb behaves differently, maybe the weather changes have a big effect.
Actually the bike has never runned really 100% since I got it.
I heard some good stories about the Keihin PWK, and ordering a pre-jetted one at JD in the US would be tempting, but shipping costs to Europe and tax will add more $.
So the cheapest is to buy it overhere.
But what kind of PWK do I have to buy exactly?
And what kind of jets, slide and needle?
I'm at sea level in temperatures between 40 and 70 degrees Fahrenheit.

Hello All,
I picked up a nice 2009 WR with 144 kit and pwk 38mm carb with custom divider (RB?) I am having a few fuel issues. My main question has to do with float height. The bike pees out the overflow tube when gas is on. Float does not appear stuck and needle seat seems clean. I measured the float height at 16mm when fuel is cut off, which is the correct height by the book.
The bike is boggy down low, then rips up top. My settings are: Main: 172, Pilot:42, red needle top clip, #7 slide, Idle mix 1.7 turns out. I am at 50deg and 200ft. Any recommendations for how to get rid of the bog and should I alter float height? Thanks!
I believe the pipe is stock (Husqvarna H0119) and fmf TC2 silencer.

Someone posted a pic on this forum of their carb, with aftermarket air and fuel screws. I actually downloaded the photo and sent it to my local Husky Dealer to see if he could get me some. It appears he can't. Anyone here know of a place where I can get aftermarket fuel and air screws for my 08 CR 125??

I'm from Southern Ontario, Canada.

Thanks All.

Its a PWK 38AS (AS is for Air Striker), Jets are real easy and inexpensive to get. It will depend on what elevation and temps you run at. I have a run of pilots from 38, 40, and 42. Before I modded my bike I ran the 40 almost always, now 38. At sea level, you might start at 42/45. For main jets I would start around a 165, or 170 and have some extras on hand. This way you can go up or down if necessary. I am at elevation, but similar temps a lot of the year. I run a 155 right now, but at 4000-7000ft elevation. Was at a 152 and 150 when it was the Summer and was running temps in the 80's and 90's F, elevations of 9000-12000 ft. I do run the JD jetting Red Needle, but if that is too expensive to get shipped to you, you can use the CEL needle. You would most likely be on the 3rd clip down from top at your location. They both work very well. I also run the slide that came with the carb. Not sure what number it is, but never had a reason to change it. My bike runs very very well. Super crisp throttle response, and no mechanical issues since I bought it. My current jetting for 40000-7000ft elevation with temps from 35-55 Farenheight is 38pilot, 155main, with JD red needle on 2nd clip from top. I wont touch it again until late Spring. That is the beauty of this carb. I have it on my YZ too, and once you get the jetting settings that your bike likes, you only re-jet a couple of times of year for changes of season.

You can get that idle screw on ebay. I bought one and it is a must have for the Mikuni!

^ yup. Sanger, Stealth Racing on eBay for the idle screw, ZipTy for the air screw.

hi all i have a wxc 250 1996and believe itsrunning too rich
it has no power lots of smoke and the spark plug is very wet and black
its had new spark plug and air filter piston is fairly fresh with loads of compression reed valves are good
any suggestions i know its the carb but just dont know how or what its so down on power at higher revs and struggles for top speed

Hallo guys,

I am new here, I bought a new WR 125 07' before some months! This is my first dirt bike so I am not very familiar with jetting. I experience this "known as I read" bogging in middle rpm. The transition from poor middle to ripping high rpm and back is really tiring and makes the bike hard to ride for me. I want to make it rev up linear.

My manual refers these standart settings for the carb which is what I use I think.
main jet .................400
jet needle ..............6DJ8-60
jet needle groove.....3rd
pilot jet .................35
idle air screw ..........1+1/2
slide ......................3.0

I am riding at 650 to 2600ft and current temperature is 41-46F.

Any recommendations on carb settings? I am considering to change to 2nd needle groove..

At least I am thinking to buy a Keihin pwk but is the carb the only problem or the power valves too?

I see yours settings are very different from mine. Is my setup too lean for may altitude and temperature ?

I've got an 02 cr 250 with stock 38mm tmx mikuni ,400 main - 35 pilot- needle on 3rd . runs well,actually idles pretty good also - but smokes like a train at low rev just crackin throttle off idle and seems to load and smoke even more when close thottle quickly (actually blows smoke rings sometimes! lol ) could this be cured somewhat with carb tuning ? any ideas / suggestions ?

Yes, you probably could benefit greatly from tuning your carb. Husky must have used the same carb/jetting settings for quite a while. I have a 2008 and it came with the same jets as yours. The proper jetting varies with temperature, elevation, humidity, fuel type, aftermarket pipes. In the fall my bike was running a 27.5 pilot jet, stock needle/clip positions, 410 main. The settings ran pretty well for me. Always begin with finding the correct pilot jet size first.

You

You could try a mix oil with a lower flash point.

your idea of an oil with a lower flash point got me curious-started looking at m.s.d.s for flash points of a bunch of different oils and found that the lucasoil im using is actually has lowest flashpoint of any i looked at. just pure luck,because until i raed your relpy,i nknew nothing of oil flashpoints! i researched a bunch of oils -maybe ill post flash point info. i found-kinda interesting

Ammsoil interceptor has a fairly low flashpoint for a full synthetic. It's about 10 degrees less than Dominator.

Hi,
can anybody say me which Needles
i shall buy fot a 144 WR?

I have a stock RB Design TMX carb on my 2012 WR144. Is it normal for the float level to drastically change after the bike's been parked for two months? The level was correct before parking it, and when I took it out for a ride last week fuel was draining out even when bike was straight (not on the the side stand). Pulled the carb, cleaned everything, and it still was draing fuel. So reset the float bowl to 6-7mm and it's a lttle better. I am going to try 8mm and see if that will stop the draining. So can the float level change just from sitting?

Thanks in advance for any input.

More than likely the float needle was /is gummed up

I don't see how the float could change just from sitting. I've never seen that happen.

same deal here. follow TROFFERs advice