EKN needle results....not so good !



17 replies to this topic
  • dieseld

Posted February 19, 2002 - 07:51 AM

#1

I finally got to test the new jetting yesterday at Saddleback MX park here in So Cal which is just below 1000'. The results....not so good.

My old jetting:

DVP needle 4th clip from top, 178 main, 48 pilot, 65 starter, 100 starter air, fuel screw 2 turns out.

And the new jetting changes:

EKN needle 4th clip from top, 172 main, AP limited to fraction of a second (used to be about 2 seconds)

The old jetting worked pretty good - easy starts, smooth power, good torque and revved well. But it popped a lot on deceleration and the mid range was missing the snap of my old setup of WR timing and stock jetting.

Now for the EKN results - started first kick and easy starts all day, idled rough and wanted to stall in the air (this was fixed by adjusted air screw), popping on deceleration is gone - this is good.

Now here's the bad part - the mid range runs super rough, and many times there is no throttle response at all in mid-range. This condition was most apparent when I was descending a 15 second down hill with a whoop section at the bottom. When hit right in 3rd gear, a quick blip of throttle easily puts the rider over the whole whoop section. But most of the time I had to shift into 4th and grab a big handfull of clutch and gas to get any response in this part of the powerband. I learned this after having the bike fall on its face and just about put me over the bars on the first two laps :) . Where did my mid-range throttle response go ?

I did dial in the air screw and idle, but I did not get a chance to mess with the AP timing since I took my son to ride his CR60 on the pewee track for his first time (about fifty laps later I had to chase him off the track.) Could it be that the limited fuel squirt from the AP is causing a lean condition in mid-range ?

Any responses from our jetting Gods is much appreciated.

Thanks

  • Taffy

Posted February 19, 2002 - 08:24 AM

#2

try two tests
1)drop the needle two positions

2) drop the MJ to a 170 and only drop the needle one position.

i've not kept JD's needle chart but maybe someone will feed in the two needles and their clip positions. then report here what position makes the tapers start at the same time.

someone do that?

Taffy

  • YAMAKAZE

Posted February 19, 2002 - 12:52 PM

#3

Thats Strange...My mid-range with the same needle will almost pull my arms off. I don't see what your PAJ is...Taffy had me drop the main from the 175 to the 170 and drop the Pilot Air Jet from 100 to 75...This has been a good setting for mine until doing the YZ timing last weekend, I now need to go up to a 48 Pilot so I can get my airbox lid off again....Too lean otherwise.

[ February 19, 2002: Message edited by: YAMAKAZE ]

  • Taffy

Posted February 19, 2002 - 01:07 PM

#4

kazi

you certainly plough your own furrow.

Taffy

  • dieseld

Posted February 19, 2002 - 02:29 PM

#5

Taffy -

Unless I am really missing the ship on jetting concepts (which could be), I think that both of your suggestions will lean things out in the 1/2-WO throttle range. So I am left to assume that you feel the problem is a rich condition at that throttle position - is this correct ?

It would not be the first time I've missed a boat, so please square me up if this is the case.

Damon

  • John_in_Long_Beach

Posted February 19, 2002 - 05:24 PM

#6

You are exactly correct, go one clip richer on the needle.

See my setting below for comparison.

  • dieseld

Posted February 19, 2002 - 07:58 PM

#7

Hmmm, Taff says to drop the needle, so I think that this means to raise the clip from #4 to #3 - and this would lean things out in mid throttle...I think.

Or should I read 'drop the clip on the needle' as would be suggested by John when you said to go richer on the needle, as I see you have by running in clip #5.

Are we all counting clip settings from the top ?

And while on the subject, what ride or sound qualities determines whether you are seeing a lean or rich condition ?

My thought is:

lean - detonation, overrunning, running hot

rich - no clue other than a black plug ??

So I guess I'm asking you to help me help myself here. What can I look/listen for to help make the decision of where its running rich or lean ?

Sorry if it's a stupid question, but I don't think I've seen anyone ask before.

Damon

  • Taffy

Posted February 19, 2002 - 11:16 PM

#8

i always say what you do to the needle, it's come from years of experience at getting confused. you should only say to "lift the needle" or to "drop the needle".

the reason that johnin longbeach is richer is because he continues with the 235MAJ that i tested in "jetting Q's". you have to go 10 richer at least on the MJ. his needle is set quite high and could run SHARPER AND CRISPER like you if you both dropped the needle.

damon, yes i think you're running a little rich. you're supposed to feel the bike, you know FEEL IT!!!

that's the best way to learn. all you need from us is to be sent in the right direction.

Taffy

  • dieseld

Posted February 20, 2002 - 11:16 AM

#9

Yamakaze -

After your question about the MAJ, I looked at the exploded view of the carb and tried matching Keihin terms to the terms used on this site (no easy task.)

This is what I believe I have:

Pilot jet (slow jet) #48
Needle EKN #4
Main Jet #172
Main Air Jet (starter?) #65 was #60 stock
Pilot Air Jet (no screw)#100 was #75 stock

Did I mix up the MAJ and PAJ ?

Now that I hope I have the right terminology, I see that I am way far from you on the MAJ. According to Taffy you are using a MAJ modified to #235 ? Seeing that I am far from this, could this help my problem with lack of mid-range reponse ?

Damon

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  • Taffy

Posted February 20, 2002 - 11:24 AM

#10

Damon

read carefully

your PAJ was #75 and is a #100
your MAJ is unchanged, as is kazi's at #200. it's john that is on a #225/235

your starter jet was a #60 and is a #65.

Taffy

  • dieseld

Posted February 20, 2002 - 11:39 AM

#11

ok ok, so beer and jetting don't mix....for that matter maybe work and jetting don't either.

Seriously, thanks for setting me straight there Taff, I knew I was mixing something up.

So I'll try it again:

Pilot jet (slow jet) #48
Needle EKN #4
Main Jet #172
Starter jet #65
Pilot Air Jet #100
Main Air jet #200

Damon

[ February 20, 2002: Message edited by: Damon ]

  • LarryCO

Posted February 21, 2002 - 07:22 AM

#12

Damon,
I strongly recommend you sending a personal message to James Dean...asking him for a copy of his new jetting spreadsheet. It's only $20 (to recoop his development costs) and is definitely worth your while. It'll show you the impact of jetting changes thru the entire throttle range. For example, you put in your current jetting...and put the same jetting in with a different clip position (like Taffy recommended for eg) and it'll graphically show you the affect of that clip position change.

By playing around a bit, you'll soon understand the impacts of all jets (pilot, jet needle and clip position, and main jet).

Once you figure out your jetting, it'll also show you impacts of temp and altitude changes...so you can change your jetting to keep the same fuel mixture through all throttle positions. Helpful when you go on trips to vastly different altitudes...

Larry

  • WRFUN

Posted February 22, 2002 - 11:15 AM

#13

Damon,

Get JD's jetting guide. I did... and I understand alot more now. If people can spend $5.00 for a magizine, $20.00 for this guide is cheap. Maybe JD can add some pin-up girls for spice. :)

Pete

  • dieseld

Posted February 22, 2002 - 11:38 AM

#14

Ok, thanks for the recommendations guys. I'm into getting the guide from JD, but I'm on my own for this weekend since he's on vacation (so I saw in another forum.) So I'll head up to Adelanto this weekend after doing Taff's recommended change of dropping the needle by 2 notches. I'll have about two hours to tune before my race.....we'll see how it goes.

Damon

  • dieseld

Posted February 24, 2002 - 06:53 PM

#15

Good call Taffy, I dropped the needle two clips and it fixed the mid throttle hesitation. My bike is running better than ever !

I raced Adelanto this weekend and it was a dead engine start. The bike started easily on the first kick, ran strong right off the bottom and wouldn't be stalled, crisp through mid, and revved well enough to carry a gear without shifting up in many situations. The deep sand was a torque fest and my WR ate it up. It was sure fun picking on the YZ pilots on the long street runs - right as they max out, I shift to 5th...later !

Thanks for the advice...you were spot on !

Damon

  • Taffy

Posted February 24, 2002 - 11:05 PM

#16

Damon

it's difficult to say things sometimes without them being taken the wrong way. saying something negative and doing it for good reasons is an all round loser isn't it.

buying JD's jetting chart is fine but understanding it is another thing all together. he has twice given me a free copy leading up to when he started to sell it. he deserves some dosh for the hours he has put in. but i don't understand it so how the F... anyone else can i do not know. what conclusions am i supposed to draw? are we here to bench race or to get the bloody things running right? make your minds up.

but at the end of the day nobody here has said it helped me to make the right decision. it might help you to learn what you did on hindsight!

i know this carb better than anyone in thumpertalk and having raced and tuned over 20 years i think i know what i'm on about.

"jetting Q's" has full and hands on explanations of what to do and what each action does. it's free and it's written in laymans terms.

JD's jetting guidance has remained unaltered for over a year and is virtually the same as the day he started offering up the EKP needle. he hasn't owned a wr for a year now.

we now have the ridiculous situation where the suzuki comes with a #60PAJ as standard and their jetting is more advanced than the WR page. they've proved far less dogmatic and it's been helped by jason pettis passing on in simple terms what needs to be done.

AND STILL SOMEONE CRASHES THE PARTY AND SAYS EKP!

"the missile" and one or two others have tried the EMN and the EMM along with the correct PC jetting. whilst everytime someone hits a lean spot and they enlarge the PJ (no names above mentioned!!!) it sets the jetting back on this page weeks.

damon, the #235MAJ was tested by me as the wrong direction. JD and aussie andy made a mistake, they were wrong. you need a #160MAJ and then down 10 on the MJ and up one position on the needle.

look around you, read, there are two or three people here with superb jetting and all those with different numbers to my recommendations are still asking questions.

K from NH still hasn't done his jetting for a year! he daren't even ask me anymore 'coz i'd like to kick his arse and he knows it!

so copy "the missiles" jetting. or copy mine and add 10 to the MJ and drop the needle one.

by the way my info still comes completely free.

Taffy

  • LarryCO

Posted February 25, 2002 - 10:33 PM

#17

Damon,
Sorry if I misled you a bit about JD's guide. Taffy's right in that it wont help you dial in your jetting (it's not the magical answer to all jetting issues)...but WILL atleast help you get an understanding of how changes in each of the jets will affect your fuel mixture across all throttle positions. The best way to get your jetting dialed in is by taking people's advice out here, trying out their jetting as a starting point, and making educated changes based on your own testing.

Just wanted to make that clear...

Larry

  • LarryCO

Posted February 25, 2002 - 10:34 PM

#18

Damon,
Sorry if I misled you a bit about JD's guide. Taffy's right in that it wont help you dial in your jetting (it's not the magical answer to all jetting issues)...but WILL atleast help you get an understanding of how changes in each of the jets will affect your fuel mixture across all throttle positions. The best way to get your jetting dialed in is by taking people's advice out here, trying out their jetting as a starting point, and making educated changes based on your own testing.

Just wanted to make that clear...

Larry




 
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