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

[Johnnymannen]

More testing today, 175 main and the blue vesus red needle. The 175 is very good for the top end, 180 slightly too rich. As for the needles again the bike runs best with the blue needle in the top slot very clean and smooth. Is there any difference between the two? I'm sure there is but to be honest I found it a difficult call. I would say I prefer the power delivery of the blue, but suspect that if someone swapped them without me knowing I wouldn't know the difference. I would be delighted if I could find a little more bottom end, I might even get a powernow.

The red needle is leaner from the bottom and richer on the top then the blue. If you want a stronger bottom go for keihin´s own needle named CEL, or for more middle and top end power use the EEL. I have tried them all and after that they were dynotested and proven. As i go iceracing now and use very much wot i have the EEL needle now, and when i go for woods i use the red JD in 1st or 2nd clip for a smooth powerdelivery. I never use the blue needle. Too rich on very light throttle for me and easier to clog up the plug, especially in the summer.

Johnny

 

[windsurf]

The red needle is leaner from the bottom and richer on the top then the blue. If you want a stronger bottom go for keihin´s own needle named CEL, or for more middle and top end power use the EEL. I have tried them all and after that they were dynotested and proven. As i go iceracing now and use very much wot i have the EEL needle now, and when i go for woods i use the red JD in 1st or 2nd clip for a smooth powerdelivery. I never use the blue needle. Too rich on very light throttle for me and easier to clog up the plug, especially in the summer.

Johnny

I wouldn't have thought the needle would have any effect at "very low throttle"? but as you mention it I would say at that at the very bottom end it is slightly rich. I was putting that down to pilot though. I will re-try the red needle again in top clip and see how that goes. Unfortunately I don't have any of the original Keihin needles to try.

 

[Johnnymannen]

I wouldn't have thought the needle would have any effect at "very low throttle"? but as you mention it I would say at that at the very bottom end it is slightly rich. I was putting that down to pilot though. I will re-try the red needle again in top clip and see how that goes. Unfortunately I don't have any of the original Keihin needles to try.

Both pilot and needle affects the very light throttle opening. As soon as you touch the throttle you lift the needle, so it does make difference! Not much, but it does. I tested all needles on the street with supermoto wheels and long gearing, and then i could really feel any changes that i did. My goal was to get as clean running on the street as possible. I even had the EEM needle for a while and that one is even leaner right off throttle. CEL is the best choice for strong bottom end power.

Johnny

 

[windsurf]

Both pilot and needle affects the very light throttle opening. As soon as you touch the throttle you lift the needle, so it does make difference! Not much, but it does. I tested all needles on the street with supermoto wheels and long gearing, and then i could really feel any changes that i did. My goal was to get as clean running on the street as possible. I even had the EEM needle for a while and that one is even leaner right off throttle. CEL is the best choice for strong bottom end power.

Johnny

Thanks Johnny, I'll try the red needle again in the top clip. I will try to get a CEL needle, I guess it will be one of the std ones used in the KTM EXC. It can be quite difficult to get anything like needles, jets etc here in Australia. Where did you get your race head from? I would like to test one if I can buy one. I did ask our local Husky dealer who said he hadn't heard of one.

 

[Johnnymannen]

I ordered both needles and racehead from JP Powersports in Canada. I don´t know if the racehead still is in the productionline, but they had at least one for me. Makes the bike stronger everywhere. If you like more topend power you can use the EEL needle!

 

[windsurf]

Thanks Johnny, I'll try the red needle again in the top clip. I will try to get a CEL needle, I guess it will be one of the std ones used in the KTM EXC. It can be quite difficult to get anything like needles, jets etc here in Australia. Where did you get your race head from? I would like to test one if I can buy one. I did ask our local Husky dealer who said he hadn't heard of one.

Johnny - more testing today with the red and blue needle, I think you are correct. The red needle is crisper at very low throttle - much better. However at wide open throttle with the 175 main it's too rich. I changed the main down to 172 and perfect, it now revs out cleanly and good top end power. The blue needle is obviously richer at the bottom end and leaner at the top. I am still using the top needle clip for best results.

 

[utopia]

Year & Bike Model = 2009 WR250
Carb = Mikuni
Pipe & Silencer =Stock
Other engine mods = none
Premix ratio & fuel type = 40:1 and 91 octane no alcohol pump gas.
Temperature range (deg F) = 55 degrees F humidity 43%
Elevation (feet) = actual altitude is 900 ft. air density altitude is usually between 1500ft and 2500ft in this area but I have seen 3500 ft air in the humid summer.
Main jet =390
Pilot jet = 35
Needle = E16BFY43-74 stock
Clip position = middle or 3rd from top
Air screw setting = 1 1/2
Slide = stock
Conclusions/Results = Crisp and responsive all the way through, air screw is very responsive 1/2 turn makes a big difference. At wide open in 5th gear it flattens out just a hair but this is at 70 mph which I will never come near in the woods. The flat spot would probably come out with a 385 or 380 main but I don't have one to try and it only does it in lower gears when you are late to shift.

I tried dropping the needle 1 clip but it would lean ping or rattle at certain part throttle positions. If I was at a higher altitude I think 2nd clip would be perfect.

I'm still not sure why everyone is avoiding the Mikuni, it's been good to me so far.

I'm curious as to how you ended up with such a lean main jet.

 

[Johnnymannen]

Johnny - more testing today with the red and blue needle, I think you are correct. The red needle is crisper at very low throttle - much better. However at wide open throttle with the 175 main it's too rich. I changed the main down to 172 and perfect, it now revs out cleanly and good top end power. The blue needle is obviously richer at the bottom end and leaner at the top. I am still using the top needle clip for best results.

Nice to hear! As it depends on humidity and elevation you always have to do the last finetuning after you know which way to go! It´s quite intersting when you learn how to change the character of the engine for different purposes! We have around Zero degrees Celsius now and i use 182 main and EEL needle in middle clip. Rich, some people say, but it deliveres power! I want to be safe too as we are iceracing and are on WOT ALOT!

Johnny

 

[lankydoug]

I'm curious as to how you ended up with such a lean main jet.

I started with a 450 and kept leaning it out one step at a time and it just kept getting better. It had a bad rich bog on top and would pee fuel out the vent when the bike was tipped a little so I lowered the float a very small amount and then started leaning the main out one step at a time. Each time I went a step leaner the bog lessened. There is still a tiny flat spot on top but as I wrote earlier I didn't have a smaller main. I know it may sound lean but I was just giving it what it was asking for. Currently is is as perfect as I could ask for since the small bog is way up in the high rpm range where I would only take a 125.

 

[utopia]

I have tried everything from a 390 to 460 and my power still flattens out at the high end. I thought something else was wrong, but at 6,000 ft maybe I need to try going leaner.

 

[lankydoug]

I have tried everything from a 390 to 460 and my power still flattens out at the high end. I thought something else was wrong, but at 6,000 ft maybe I need to try going leaner.

As I went leaner on the main the flat spot got smaller and moved up higher in the rpm range. Where it is now I will never feel it because I would have already shifted long before it goes flat. If yours was improving as you went leaner keep going, if it gets too lean it will try to ping or lean stumble and you can go back. Just don't stay in the throttle on a lean spot, if it rattles or pings go back richer.

 

[Vinduro]

Testing went well. So far good throttle response with no blubbering. 60 degrees today. We will see how it does next weekend at the H/S at Tree Farm, in Alabama. I noticed that the stock 7 slide in the 36mm had a 3mm groove in the middle of the slide. Right in the middle just in front of the needle jet nozzle. It now has the 6 throttle slide valve. 35 pilot. A/S 2 turns. 170 Main. NOZI needle , #4 position. FMF Fatty Pipe. The P3 pipe guard fits but fits poorly. Had to turn the rear pipe mount around backwards. No need for the nut as the FMF Pipe rear mount has a nut welded on. Had to dent the pipe a tad so the kickstarter would not hit when folded. Pipe springs much easier to install with the FMF pipe.

 

[Joe Chod]

True True on the pipe springs. Whoever dreamt up those "notched tangs" vs. the standard "U" loops must have been a masochist or from the "Italian home for the criminally insane!" The original pipe (the one that the seams were prone to busting) has the traditional closed loop mounts and the Husky replacementy has those FUBAR notched tabs. Next time the pipe comes off....so do those things and new loop type spot welded on.
Dwight, on the PV springs, are you prefering to open as late as the stocker ....around 8000 RPM ...am guessing a seat of the pants feel... (thereby retaining the sweet low end) and just modifying the stock spring to get a slower/more progressive opening?

 

[Vinduro]

I am using the silver spring from Walt. It was installed at Halls Cycles so I don't really remember what exact combo it was. The bike has great low end. Although this weekend I stayed mostly on the pipe during the H/S . I checked plug after the event and it is still pretty dark. Mostly at the lower RPM range but the serious BOG is gone. I do have a bit of low rpm hesitation that I can't decide whether I need to drop the needle ( I will test that next weekend) or it is just the large carb on a small bore. I still have the 36mm on the bike. This weekend I did suffer the indignity of getting passed on the straights and trying to make it up in the tight. Just hard to hold off a 450 on loose uphills and LONG straights. My top speed for the day was 54mph and Guys were passing me about 10 mph faster at times. Still tickled with the bikes handling and suspension. Another reason to drop the needle one is that I am getting spooge at pipe end / connection and terrible fuel economy. Slightly over 14.3 mpg this weekend. I burned 3 gallons in 43 miles. I dumped in 1/2 gallon a end of first lap. I will be changing also from Maxima Super M to Maxima K2 this next weekend. Told it burns cleaner, Protects better and develops more power.

 

[marcmo0]

Any rockies guys (high alt) w 300's? Wondering what your settings are. I keep getting a sputtering up top and then it revs off. I have 09 300, 4k-7k elev, 40-70deg, jd red #2 and 40 pilot

 

[marcmo0]

Oh, and a 168 main...

 

[windsurf]

Any rockies guys (high alt) w 300's? Wondering what your settings are. I keep getting a sputtering up top and then it revs off. I have 09 300, 4k-7k elev, 40-70deg, jd red #2 and 40 pilot

I dont know if this is relevant as I'm at sea level, but with simillar set up. There is quite a difference between #2 and #1, my bike doesn't run that great at the top end in #2 but very strong in #1. I have also just ordered a CEL needle and will also try to get the EEL. It seems that these needles give good results and may be preferable to the JD needles, time will tell. What is interesting is how much small changes make.

 

[Vinduro]

OK, I have readjusted my float level AGAIN. I have changed to Maxima K2. I ran the bike this weekend at the Cajun Classic Nat'l Enduro. I got 5th after a weak showing in the first section but the rest of the day went pretty good. I am still running the Keihin PWK 36mm Air Striker from the 2011 KTM 150XC. I am running the 170 main jet (Stock), 6.0 slide / throttle valve ( stock is 7.0), NOZI needle in the #3 position (Stock), and a 35 pilot jet. I had to adjust the Air Screw out to 3 turns. ( I plan on dropping it to a 32 pilot. IF I CAN FIND ONE).​

Carburetion was very very good. Bike ran better than ever. Little to NO spooge at pipe connection. My milage has now gone from 14.3 mpg to over 18 mpg. At first gas stop I figured I was getting about 20 mpg. Next two gas stops I was getting a bit over 18 mpg.​

 

[Vinduro]

Is there such a thing as a 30 or 32 pilot jet in the PWK 21 series Pilot jet ? If so where can I get one ? The smallest I can find is a 35. The bike is running pretty good. Just feels like it is a tad rich at bottom and needs a smaller pilot . I have a 35 in right now. I have to turn the air screw out 4 turns before it starts to idle upward. I have always been taught to adjust the pilot to where you are 1.5 to 2.5 turns out at max idle speed. Then reduce idle with idle screw. I went from the lean 7.0 slide to a 6.0 slide, would a 6.5 help lean the pilot without making the 1/4 to 1/2 throttle lean ?

 

[Pinittowinit]

On the jd reds you guys get how many lines are on it?