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

If you have a Gnarly pipe I would start with a 440 main and a 35 pilot with GAY needle in the middle. You could always lean it a bit or if needed go richer but it's going to be close.

Running a brand new stock pipe that I scored and Yamalube at 32-1 and shxt gas at around 50% humidity, thanx.

I need some needle suggestions as I have still not cracked the Mikuni code. A list of needles is here http://www.cafehusky.com/threads/various-tmxx-needles.22569/ along with my long winded description of where I am at the moment.

To keep it brief here. The 6chy16-61 (an optional Rm needle) works fairly well with this jetting (27.5, #5 slide, clip 2.5, 460 main). I tried the stock needle, 6dey15-74, and it works even better. I think it might be a tad lean in the lower third though. I tested it at (27.5, #4 slide, clip 3, 460 main). What needle from the above link might be between the two, or like the stock on but just a tad richer on the lower third of the throttle? Does anyone have any ideas?

Thanks

Year & Bike Model = 2006 Cr125 w/2008 144 Cylinder
Carb = '06 TMX38 old style
Pipe & Silencer = FMF Fatty + FMF S/A
Other engine mods = 2008 144 Cylinder
Premix ratio & fuel type = 32:1 Maxima Castor 927 + Pump premium
Temperature range (deg F) = 40 - 110
Elevation (feet) = 100 - 3700
Main jet = 400
Pilot jet = 35
Needle = 6DJ8-60
Clip position = 3rd
Air screw setting = 1.5 turns
Slide = 3.0
Conclusions/Results = Stutters and breaks up when hard on the throttle, raising the needle all the way helps a bit.
A week later 02/19/12- Went to a 30 pilot runs well up to 1/4 throttle, starts 1st kick. 1/4 throttle up make a "crackling" sound when hard on the gas. Eric Gore literature describes this is too rich. Raising the needle moves the "crackling" higher into the rev band.

Any thoughts on 144 conversions with TMX38 old style carbs?

My thought now is to go to a leaner nozzle (needle jet as opposed to a jet needle), because this is the leanest needle that Husky lists. Anybody know of a leaner needle than 6DJ8-60?

Can anyone confirm that the needle for the older style Mikuni TMX38 w/the rectangular slide is different (shorter?) than the needle for the later oval slide TMXx38? The RM needle won't work in the older style Mikuni TMX38 w/the rectangular slide, right?

Thanks,
Craig

I just measured a 6dj8-61 and a 6dj8-62 and the 62 is fatter so that would be leaner.61 and 62 are leaner needles.
Bill

Do you recall where you got those needles? I need to get some- the kid is pestering me to ride after I got it punched out to a 144.

Got them from my Husky dealer. I just looked at your Jetting specs and They are close to mine I am running
390 Main
60 needle in the second groove
32.5 pilot Jet
Air screw 1.5 out
3.0 slide that was with my bike as a 125 and now the same jetting as a 167
Elevation is about the same temps are a little different but that's what I run in the summer here in NY
Bill

Mine is making a "crackling" noise under load at 1/2 throttle and up. An Eric Gore tuning guide says that is rich, although I've never experienced it like that before, but I'm used to antique pre-reed valve bikes that just go booowahhhhh... It's got a new Fatty pipe and a new 144 top end from Walt, so I'm dealing with two new things at once. I'm down to a 30 pilot and it starts 1st kick and idles and revs quick with no run-on. Breaks up in the middle and screams on top.
I just sent out a bunch of e-mails to local dealers seeing if they have a needle in stock.
Thanks for your help.

My local dealer is mainly a H-D dealer, so I have to wade through leather fringe and polishing kits to get to the parts counter only to be told I need to get a Harley. Makes me feel like I'm 14 again- and not in a good way. We get into discussions about how well a H-D can jump.

Try going up one groove at a time on the needle , don't try too many changes at a time to get things confusing and keep checking the plug to make sure you don't get into a lean condition. You might want to think about the Keihan A/S carb.

I am going to start racing. Any good bikes you have in mind. Looking for a 2 stroke 125 or 250. Something like that. If you could help me that would be great.

I've been thinking about that. Is it a $275 magic bullet or just a new can of worms?

What kind of racing? 2 strokes are reliable and cheaper and easier to maintain. If you're getting a used bike, 2 strokes are less of a gamble as to what condition you're getting. How about riding your 410 in an Enduro or hare scrambles?

Did you talk to John01 to find out what needle#/slide is in my old carb?

I think it is 6DGY12-59. JETS R US has them for $7.00

Another option, Walt has a Keihin 38AS of mine and some of my needles. You could contact him if you want to try it?

Just make sure to use it without rear divider in it.

If you have correct needle and slide for your TMX, send me your carb and I can cut it/divider it/ drill a hole and get it jetted real close. I can get that older carb to stand that bike up in the air.

It is pretty heavy tho, not only that it is front heavy. That is the only issue I have with racing that bike.

Huskys are famous for being stable, just run everything over. Y'know like they say in Oregon, "Just do it!"

Hello,
I am chasing jetting setup for a 2009 WR250. I have the stock TMX carbie but have just added a Pro Circuit pipe and muffler. I ride at sea level to 1500 feet and use 98 octane fuel at 50:1. Any help would be much appreciated.

And almost forgot...have a JD jetting kit on order.

Check the jetting data base, You'll alot of info there.