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

My bad, main is 390.
And yes it is the mikuni tmx with square slide.
I have the iridium plug from ngk #8 , last time i checked plug was on the black side.
After that i put the needle clip to 2nd from top and screw 1,6 out.
Now i need to check again, but being my first enduro husqvarna i am curious of they are al sluggish @ low rpms?
My previous motocross bikes, kx250/ rm250 did not hesitate when opening the throttle.
Now i work the clutch in slippery corners to avoid the hit, normally wit a 250 this is not neccessary.

OK makes sense now. That jetting is pretty lean and no the engine should run crisply from idle. Maybe you are having a lean bog? That jetting should not be too rich. I am running a 37.5 pilot, stock needle 3rd clip, and a 380 main right now. Just came back from an MX track 60 F and the engine was running great.

Ok thanks, what sprockets do you run?
Will set it richer and see how it goes.

Oh rats! I just realized I was wrong on the pilot size! I am running a 27.5 (stock is 35) on my bike. If you have a 35 in you can try going to a 30 or 27.5 to clean up the bottom. My bike was really rich with the 35.

G'day, I'm trying to tune a tmxx on wr125 (2013) and have a question. I'm wondering if anyone has tried a richer needle jet, perhaps an R9?

I'm running a 17.5 pilot and #5 slide and am happy with the idle to 1/4 throttle performance.

I've noticed however when doing main jet testing that I couldn't get to an obviously rich setting, I even went ridiculous and fitted a 580 main jet, just to experiment, and didn't have excessively rich symptoms at full throttle!! I've settled on a 490.
I'm also running the needle at clip position 5 on both needles supplied, 6bfy45-74 & 6dey15-74. I settled with the bfy as the dey had a slight hesitation when cracking the throttle from 1/4 to 3/4. I tried the rm needle 6chy16-62 but this was too rich at 1/4 throttle and still had hesitation mentioned above.
I noticed as well that throttle response when opening from 1/2 to full seemed to improve with the choke on with a 540 main jet fitted.
While riding the engine returns to the set idle speed with no hanging up in the revs. This to me eliminates air leaks.
All this has me questioning the needle jet.

Changed pilot back to 40 and the bog when smacking throttle from 0 to 100% has improved...
Thinking of trying even some bigger sizes of pilot.
Left the 61 needle in as this gives me a more crisp midrange.
Maybe i try the #4 slide also.

Just to update: I went to my local carb specialist outlet looking to purchase the R9'needle jet to be told it's a husky only part and no listing exists in the mikuni book.So I was faced with the prospect of having this little gem of an engine running good but not great......I couldn't do it.......left his store with a PKW38 air striker!!
I've just fitted it, the cable adjuster took a bit of fiddling, fired it up and been for a gentle lap around the block. It seems to run crisper down low than the mikuni did....and I haven't tried to tun it yet!!!

Probably a wise choice mate. I was gonna' say you're way rich on your main and too lean on your pilot. My oldschool method is go rich, especially on the MJ, until it blubbers and spooges, then lean it out a step at a time.
Good luck with the PWK, the 1st 10-20 pages of this thread are a lot of Keihen tuning with great info.

cheers

I just brought the wr300 home last Monday and it ran like shite. Old, maybe cheap, gas was part of the prob, but also lean on top and blubbering and spooging in the middle. After checking all the basics I did 2 20 mile rides, so @ 2 gallon of fresh 100% gas w/50:1 Interceptor. That helped a little, it starts pretty easy, smokes a little and was still blubbering through the middle in every gear and spooging all over.
First thing was to order some jets and gaskets. I didn't want to spend $100 on the JD kit because I plan to replace the carb in a month or 2 and thought with all the info here I could get the Mik to work for now. I ordered the 6sigma jet kit (@ $40) for my bike and altitude and that's done the trick for my altitude and temps, though I'll probably lean it out some more when the cold weather sets in.
I ordered 2 cr250 reed block gaskets from the local Honda dealer also and installed them on either side of the reed block after cleaning it all up really well.
I'm 2nd owner, the bike had less than 10 hrs on it and carb was stock. It was set up by a BMW dealer in Raleigh, so low elevation. I'm riding at 2000-4000' , fast fire roads and greenways, steep hills and single track.
I found the carb had 420 mj, 45 pj, GAY needle 3rd slot and that the float was @ 18mm. I adjusted the float to @ 14mm, 6sigma sent a 37.5 pj and I went to 450 mj and left the needle as is, AS is @ 1 1/4 out. That helped a lot, no more spooge!, but 1st-3rd was still blubbering in the middle. Then I moved the NJ clip to slot 2 and that's cleaned up the middle pretty well. It still needs some fine tuning, but at least it's rideable and doesn't puke fuel when on the kickstand.
The other noticeable change is the starting ritual. Cold, I was leaning the bike until it pukes gas, full choke, no throttle, kick a few times, wait, kick it hard and it would start and idle. Warm, it would start 1 kick with no throttle. Now that it's leaned out on the PJ and needle I still lean it 'til it pukes, full choke, and give it throttle as I kick, starts 1st kick cold and warm (with no choke).

Do note that float level is critical, especially with a rich MJ. If the float level is low and you run WOT the engine can starve and seize!

The 6sigma kit included:
3 MJs;
1 PJ;
2 NJ shims (1/2 clip step);
1 nylon spacer;
a drill bit and removal screw for those with sealed AS;
and 10 pages of instructions with pics.

chees

Ooops, spoke too soon. Next day it started hard cold and spooged again
Today installed BR8 Iridium plug and 430 MJ, started 3rd kick, rode it until it was hot, fine tuned idle and AS again. Now she starts easy again and only a little spooge after a 20 mi ride and some blubbering at the start of the mid range.
I'm ordering some leaner PJs now which hopefully will help.

cheers

The colder weather on its way is also going to lean out your bike's jetting...

2009 WR300 PWK38 I'm running a 175 main presently and the bike runs great at 60-70*F now that the temps are dropping how many jet sizes do you usually jump up for 10-20*F temps?

Got a 2000 CR125 stock piston and head/ports etc.

Has a pro circuit platinum and pro circuit spark arrestor nature friendly silencer. Uni foam filter.

Jetting was "6EJ2-60" needle at the TOP clip so leanest setting.

Main 400

35 pilot

Air screw was only .75-1 turn out.

Plug is wet with fuel and dark up. Bike starts first kick without the choke, and seem to run really well but the concern is with the plug being fuel wet at idle seems rich, and the bike does not seem to rev out the high rpm quite as good as it did with the old silencer. The old was a wide open pro circuit with no packing and tons of leaks.

Any tips? The needle clip position and still being rich seems odd. It really has a bad bog now at low rpm. But once out of it it really rips!

Searching info for Lectron? What, a carburator without main jet? How does it work? Is it worth it?

And then as a new hva owner i need jetting tips for winter ride and summer ride.
I live in Finlands so winter is cold. its like -10 to -30 celsius.. Mostly -20.
Summer is like +20.
Carb is original 38 tmx

Thanks!

http://www.cafehusky.com/forums/motosportz.30/

What are reason why people change stock carb (TMX 38) to PWK? Should I? And where the f i can find it...

Sorry for double posting!

And if i find a pwk somewhere, which is better? 38 or 36?

Hi Guys

Looking for some help here with my 2013 WR250. I want to eliminate the major spooge problem that I have. After a year of running the stock Mikuni, I switched to the JD 38mm PWK AS and ran it on its stock settings, but that really didn't help things. I then tuned the JD by switching it to the red needle on 3rd position from the top and that didn't help either. Most recently, I switched my jetting to a 42 pilot, 172 main and red needle in third position from the top. But, its still smoking and spooging. I have been using Maxima Super M in ratios ranging from 44:1 to 50:1. Most of my riding is woods in the Northeast US.

Any tips on how I can avoid the spooge and smoke problem? Im going to try to put it into the second clip position from the top and use Amsoil Dominator at 50:1 next, but im not sure if that will help. Thanks.

What was your original pilot jet on the PWK? On a KX I had; I went all the way down to a 35 pilot at times. Where are you at in the Northeast by the way?

Original JD pilot setting was 45 and Im at sea level