EKN needle results



23 replies to this topic
  • John_in_Long_Beach

Posted February 28, 2001 - 08:42 PM

#1

I just put in the EKN needle and zipped around the block. Here are the results. 1st thanks to everyone for their help with their settings. It's great not having to "re-invent the wheel"

Previous settings

2000WR, YZ timing, DSP tapered header and pipe, DVP#4, 180 main, 48 pilot, 100 pilot air, airbox lid off, about 1 5/8 turns out, sea level, 55 degrees

The DVP worked well, very linear, it had good grunt 0-1/4 throttle (probably more a result of a 48 pilot), but then required more turning of the throttle for more power from 1/4 - 3/4 throttle. This provides good control for trails, but I thought that I would try the EKN.

New Settings

Everything the same except

168 main, EKN#4, 1 turn out.

Having just taken it around the block a couple times (didn't want to piss the neighbors off), I can say that the powerband feels more continuous. The greater power from 1/4 - 5/8 make the powerband feel more continuous.

Now power flows from idle to 5/8 throttle (haven't really max'ed it out). As for a DVP being more controllable in the trails, I can't say. But it is my guess that the EKN needle may actually be more controllable. I will explain. With the DVP, different amounts of throttle are required for the pilot jet (0 - 1/4) and then the needle (1/4 - 5/8) for the same power change. The 48 pilot with my bike and the YZ timing picks up revs extremely quickly but then the DVP mellows the power band. Two separate characteristcs. The EKN on the other hand continues the bark off idle, for a much more continuous feel.

Now these initial observations are only with a couple of laps around the block so hopefully I will be able to confirm the initial settings and/or any adjustments.

Any suggestions or comments would be greatly appreciated.

John

  • James_Dean

Posted March 01, 2001 - 01:48 PM

#2

John,

Thanks for the feedback on the EKN. I'd have to agree with your impressions. Have fun!

James

  • John_in_Long_Beach

Posted March 04, 2001 - 09:30 AM

#3

I just have to rave a little more about how much FUN the EKN needle has made the bike. I was blasting around the neighborhood yesterday. The Wheelie factor is just great. I kept on wanting to wack the throttle open and pull whellies. The DVP needle was responsive, but too tame). The EKN is more ballsie, more grunt, more motion with less rotation, more intuitive in how the bike reacts. The engine and the power that it produces now feel more wired to my brain.

The fun factor certainly went up. With just a needle change, the entire character of the bike changed.

[This message has been edited by John in Long Beach (edited 03-04-2001).]

  • mcarp

Posted March 04, 2001 - 07:33 PM

#4

Thanks for the great post. I REALLY like the EKN as well. If you like the EKN, you may like the EKP even better. Instant grunt, less throttle with YZ timing0-it's a hoot!! Thanks James for kicking us lazy asses in the pants to try new settings.

"Wired to my brain"...that's exactly right. I even put more play in the cables to avoid accidental overdose.

  • Clark_Mason

Posted March 04, 2001 - 09:35 PM

#5

I actually fired up the WZ420 and did a little comparison testing between two needles and the results are similar to my observations last summer. The main difference in the two configurations was the needle.

Configuration 1

PJ = 48
Fuel screw = 1.25
Needle = DVP #5
Main jet = 180

Configuration 2

PJ = 48
Fuel Scrw = 1.25
Needle = EKP #4
Main jet = 168

As before the throttle response is snapper with the E** needle the power delivery more abrupt. The DVP is smoother in its delivery and better suited for slippery surfaces. The EKP suited to excellent traction conditions and for those who love that instant wheelie although with the 420 and 13.5 to one compression wheelie is no problem in first three gears with either needle.

Every since I installed the 420 at 13.5 to on my bike has fantastic low and mid range but will not rev out like the 400 did. I think its the compression any thoughts. Since the 420 I'v been running 15/49 gearing everywhere.

Clark

  • James_Dean

Posted March 04, 2001 - 09:54 PM

#6

:)

Check out the thread on FCR tuning. The main air jet is in question for better revs. Read Taffy's link to get an understanding of why.

James

  • John_in_Long_Beach

Posted March 04, 2001 - 10:15 PM

#7

MCARP,

(or any other person who has used both the EKN and EKP needles)

Thanks for you comments, it is helpful to have your thoughts confirmed. Sometimes I think my car runs better when I wax it, so perception and reality can sometimes be different.

What is the specific difference in the way the EKP performs vs. the EKN. Have you used both in your bikes?

Just curious.

  • Guest_Guest_*

Posted March 05, 2001 - 12:53 AM

#8

Supprisingly enough your car does run better after a good waxing as it smoothes the surface which creates less friction and turbulance resulting in less resistance to move foreward, eg hit a puk accross the ice before a game(smooth surface) and then after a game(rough surface) then think of the ice being your car and the puk as air particles moving accross it.Do U believe that!

  • Taffy

Posted March 05, 2001 - 02:17 AM

#9

john
the EKP taper starts 1/2-a-clip nearer the top. the tickover is a teeny bit leaner. i wouldn't have thought you could hardly tell mcarp.

clarke

my 600sss had 14.5 to 1 compression which was way to high for an old two-valve aircooled bike. it would only rev to 8,500. by lowering the compression it now revs out to 10,000rpm which is still too low.

the combustion chamber was made for a 400 bore. when you make the engine bigger the squish gets wider. the trouble is a squish shouldn't be any wider than 8mm. you must then have a step down to a secondary squish.

if you don't alter the squish, it won't rev!

if you have the standard .080" gap (head to piston)you haven't got a squish & the problem is just the sheer compession.

correct squish is .040" (1mm).

RR doesn't mention this because ...well you know my thoughts...

Taffy

  • mcarp

Posted March 05, 2001 - 02:04 PM

#10

John-

The EKP made the bike run a little crisper. It seemed to rev a little quicker than the EKN. This was during a swap on the same day, same conditions. I even went down to an EKR which runs great, but it's a little too lean and doesn't quite have the kick the EKP does. It is a subtle difference, but with my setup it could be felt.

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  • James_Dean

Posted March 05, 2001 - 04:07 PM

#11

mcarp,

What were those conditions? if you please,

- temp, altitude, needle clip, pilot jet size, pilot screw, state of tune.

Sometimes I can't decide which to recommend. Depends on which way the wind is blowing. :)

(They are very close as you know.)

James

  • SFO

Posted March 05, 2001 - 05:08 PM

#12

my 600sss had 14.5 to 1 compression which was way to high for an old two-valve aircooled bike. it would only rev to 8,500. by lowering the compression it now revs out to 10,000rpm which is still too low.

the combustion chamber was made for a 400 bore. when you make the engine bigger the squish gets wider. the trouble is a squish shouldn't be any wider than 8mm. you must then have a step down to a secondary squish.

if you don't alter the squish, it won't rev!

if you have the standard .080" gap (head to piston)you haven't got a squish & the problem is just the sheer compession.

correct squish is .040" (1mm).

RR doesn't mention this because ...well you know my thoughts...

Taffy[/B][/QUOTE]

Taffy, There you go shooting from the hip again!
Compression and squish are only part of the rev equation.
When you put a big glob on the top of the piston you alter the cross flow of the cylinder head design. If you check this on a flow bench you will see what happens when you put an obstuction in the path.
This is why Rich asked you what pipe you were running for cam timing #s.
I love that you can make a blanket squish statement too...
THIS IS WHAT WORKS, according to Taffy...
Simmer down home boy.

  • Andrew_in_OZ

Posted March 05, 2001 - 06:29 PM

#13

John,
It's great to see you got the EKN working, It's a beauty eh!sory I didnt get back to you with my weekend results although I listed them in the FCR tuning post (been a bit to busy) If you try the EKP I would be interested to hear the results as there is only a fraction difference between the two, thanks

------------------
Andrew
"00"WR400
YZ timing,EKN needle, VORTEX dualcurve ignition
SF triple platinum s/plug
open box -unifilter
98oct fuel
Staintune s/s open exhaust& header......
Somebody stop me !!!

  • Clark_Mason

Posted March 05, 2001 - 08:07 PM

#14

James Dean

Relative to my wanting more rev out of my WZ420 I'm considering 1) removing the MAJ and seeing if any effects and then start going up in main jet sizes and noteing results. If this helps the WZ 420 rev out then great if not then I may be back into the engine take some measurments in particular deck height as taffy noted and I concure I like to run around .040" and in theory when Erik Gorr did my cyclinder he milled off some of the base gasket surface to get closer a more optimal deck height. I ran my 95 400 KTM at 0.037" with excellent results, the squish band on the head was also adjusted by Curtis Sparks. That motor was very over square at 95mm X 56.2mm and with the cam I ran a real top end machine. I was running approx 11.0 to 1 in the KTM. Now in the 91 DR454 I built I ran at 13.8 to 1 had fantastic low to mid power band but would sign off early like the WZ is doing now. However, in the WZ420 I still feel I'm fighting compression and may go back to a stock compression piston. It all depends on time which I have very little of right now.

Of course all this wanting more rev probably whining since when I drag race my friend and his 00YZ 426 which is geared up (15/47)its a dead heat until the very top and he gets me by a little.

I feel the XR650R needs a pumper carb. It suffers from lags in delivery with normal high speed throttle openings as in use during trail riding--not the whack it open like a teenager type probably would die. I have one, a Mikuni that I built up for my Husaberg 600 and may give it a try if I can make it physically fit, Any suggestions?? Again time. Maybe XR's only will develop one? I'm rambling!!

Clark

  • James_Dean

Posted March 05, 2001 - 09:16 PM

#15

Clark,

If you pull out the MAJ, look into the passage. You may want to pull the needle jet out and drill the MAJ passage. A 3/32 drill measures at 2.4mm for this. Taffy went to 3mm. The clearance around the nozzle becomes a consideration at some point. A whole bunch of other factors exist for you to consider with all the mods to your engine though.

When you were running as a 400, didn't you outrun the 426's? Or were they just not dialed in yet?

James

  • Taffy

Posted March 06, 2001 - 12:58 AM

#16

sfo

i don't know where on earth you get your facts. probably the same place you talk from.

the only explanation you offer is some kind of blob on the piston!

uncorrected figures;
400cc
92 x 60 B & S
12.5 to 1 comp
combustion chamber holds 31.9cc

425cc
95 x 60 B & S
13.5 to 1 comp
combustion chamber holds 31.5cc

the measured area around the outside of the bore between a 92mm & 95mm bore(for 1mm of stroke)is;

7.089cc -6.648cc =.441cc

so by going up in cc to 425cc & using the SAME piston bar the 3mm on the outside of the piston, we will see the combustion chamber hold .44cc more & what do we find!!!

it holds .5cc less. so we have raised the compression by finding .94cc of metal. wow!

guess you better climb that dog turd in your garden that's a mountain! that dustbin must be everest!!!

what does all that have to do with a camshaft & an exhaust?

c'mon pray tell?

i can make a blanket statement on squish because i know what the bloody hell i'm on about, do you!

squish is about gases & their compression & movement. honda don't have a special deal on it & neither do yamaha.

in tests years ago it was found that if you couldn't squeeze the gases out the way into the middle they would simply stop the piston. i was told it was 8mm if it's + or -1mm of that i don't care.

when you bore a bike out you add to the squish IMMEDIATELY. it's then up to you to "re-work the chamber".

unfortunately taking away metal then lowers the compression & we're back in that same old battle all over again.

clark, how about trying a standard ignition off a YZ just to get a back to back?

Taffy



[This message has been edited by Taffy (edited 03-06-2001).]

  • Jason_Foslien

Posted March 06, 2001 - 01:40 PM

#17

Originally posted by Clark Mason:
I actually fired up the WZ420 and did a little comparison testing between two needles and the results are similar to my observations last summer. The main difference in the two configurations was the needle.

Configuration 1

PJ = 48
Fuel screw = 1.25
Needle = DVP #5
Main jet = 180

Configuration 2

PJ = 48
Fuel Scrw = 1.25
Needle = EKP #4
Main jet = 168

As before the throttle response is snapper with the E** needle the power delivery more abrupt. The DVP is smoother in its delivery and better suited for slippery surfaces. The EKP suited to excellent traction conditions and for those who love that instant wheelie although with the 420 and 13.5 to one compression wheelie is no problem in first three gears with either needle.

Every since I installed the 420 at 13.5 to on my bike has fantastic low and mid range but will not rev out like the 400 did. I think its the compression any thoughts. Since the 420 I'v been running 15/49 gearing everywhere.

Clark



  • Clark_Mason

Posted March 08, 2001 - 08:44 PM

#18

Taffy

Don't fret we are on the same page. It was bored out to 94mm an is actually a 417cc mill at the moment. When time alows I will start working on the engine and if the last few R's to get to the Vortex ignition red line become that important to me I will take the time to sort it out and reslove it to my satisfaction. This may indeed involve a slight reshape of the squish and it may not. This is a resolvable issue if its that important its time thats in short supply.

James

Yes my modified WZ400 was faster than stock 00 426's on top but the 426's had quicker corner to corner speed--a snapper mid range. Now my WZ 420 has a snappy low to mid range but lost a little on top. Its still a very quick and fast ride once again I'm splitting hairs.

Clark

  • Hick

Posted March 09, 2001 - 10:50 PM

#19

Hey Clark,

A friend of mine races an ’01 XR 650 in the AZ Whiplash series and the occasional SCORE race. After the Baja 2000 he picked up a sponsorship of some kind from XRs Only and ended up with a Mikuni pumper on his bike. I rode before and after, and although the pipe also changed (from Yosh to Supertrapp I think) and a few months had passed I found it much more wheely prone afterwards. And this was with the extra 1,800 (or whatever) miles on it. “For sale, ’01 XR 650, ridden once…”

BTW he was obviously geared pretty tall (he was clearing this one gap in 2nd, I was lugging it in 4th ), but I stayed right with him in a drag race until I got to fourth gear…

Of course, he outweighs me and had a full tank of gas. We’re talkin’ like 5 gallons or something, the tank he had on there was insanely huge.

I don’t know the source of the pumper carb for sure, I just assumed it was from XRs Only. I just sent an email to my friend to find out, plus I will be in Phoenix this wknd so maybe I’ll get to talk him then.

Also, I read with much interest what was said about your WZ 420. I have a 13.5:1 97mm Wiseco in my ’00 YZ 444 and also noticed diminished willingness to hit the rev limiter. I don’t know squat about squish, but I’m interested in whatever you find out about this issue on your bike. I’m also going to try it without the MAJ (not sure if I’m willing to drill it, I haven’t looked at it yet) the next chance I get (unfortunately that’ll be a few weeks from now minimum).

  • Taffy

Posted March 09, 2001 - 09:27 PM

#20

clark

if you get your squish right & have to machine a little off in the right places you'll be lowering your compression the RIGHT way.

SFO or bill, is a big buddy of mine really & we just like to shoot a bit of **** now & again!

he's mailled me with a valid point. the dome on the piston would slow down the overlap at TDC on the exhaust to inhale strokes.

crankcase breather would be another reason.

i doubt all three of the above somehow.

Taffy




 
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