Where to get an "E" needle?
Posted April 10, 2001 - 02:37 PM
Posted April 10, 2001 - 04:42 PM
Posted April 10, 2001 - 07:41 PM
The EMP is a direct substitute for EKP by setting it 1 clip richer.
EMP#5 equals EKP#4, ignoring the small .9mm length difference at the tip.
I would suggest you get both EMP and EMN from Sudco. EMN for lower altitudes and cooler temp, EMP for higher altitude and warmer temp.
Since you're getting them from Sudco, get a pilot air screw & spring too with a #48 pilot jet. Set the air screw to 1 1/2 and pilot screw at 1 1/4 with the #48. Strap yourself onto the seat when you go for your first ride!!
Posted April 10, 2001 - 11:21 PM
Rcvd a e-mail from Sudco last week. The air screw is on backorder. I was not informed when (if?) they'd be in.
This will bolt up to my 99....right??
'99 WZ with all YZ mods, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, forked over by Pro-Action, OEM YZ tank and IMS seat.
Posted April 11, 2001 - 06:21 AM
Yes, the air screw will fit your '99 FCR. It was designed originally for your version of the carb. It also works on the reconfigured '00 & '01 Yamaha 'exculsive' FCR. It's pretty cool that they machined in the cavity for an adjustable air screw even when it is not needed with a simpler pilot air jet.
These must come in and out of stock because I've purchased them on 2 occasions.
Sudco part #021-230 is air screw, #021-235 is the spring that secures it. Make sure they know you want the air screw and not the pilot screw.
Posted April 11, 2001 - 11:10 AM
Posted April 11, 2001 - 02:38 PM
Try a #170 main jet first and evaluate the main only at full throttle. Probably best to start with EMP#5 (=EKP#4) and 1 (+/-.1) turns out on the pilot screw.
Posted April 11, 2001 - 02:47 PM
ekn needle on # 4 (bought when EKN was the needle to have)
45 pilot jet
200 main air jet
air screw set at 1 3/4
started without choke
2001 WR426 air box top removed and vortip from fineline
I have a stumble at 1/4 throttle
and a flat top..
However after a plug chop
the plug has a black sooty body with a clean grey electrode
Posted April 11, 2001 - 07:05 PM
The difference between the EKN & EKP is slight. The EKN is STILL the needle to have for many.
What is the temperature and altitude?
Try smaller main #170 and most likely turn the pilot screw out to 2 - 2 1/4 turns. Check the response and starting. If the low speed is too rich go back a little at a time on the pilot screw while checking response. **The pilot screw may end up less than the 1 3/4 you are at now, but most bikes are a little further out when using a #45 pilot.
BTW, you do mean the pilot screw on the bottom of the float bowl don't you?(you wrote air screw), out is richer on the pilot screw(opposite of an air screw).
[This message has been edited by James Dean (edited 04-12-2001).]
Posted April 13, 2001 - 11:24 AM
I'm at 1 1/2 out on the pilot screw. It's hard to start with choke on. It's also hard to start with choke off. It acts like it wants a mixture somewhere in between. This happens when air temp is around 60-70 degrees. When it's colder, it wants the choke and when it warmer (75-80) it does'nt want it. I'll try what you said (1 turn out) and let you know.
Posted April 16, 2001 - 03:13 PM
170 Main Jet
48 Pilot Jet
Pilot Air Jet Screw and Spring 1 1/2 out
Pilot Screw (front of float bowl) 1 1/4 out
200 Main Air Jet
Can't wait to try it. My friend has been doggin me with his YZ 426. Should be no more of that walkin away from me in the midrange now.
Posted April 16, 2001 - 08:58 PM
Looking forward to hearing if your setup matches mine.
Posted April 20, 2001 - 02:46 PM
I got it together and went for a couple of rides. The upper-mid range is most improved. However, the top-end revs are quick to show, but lacking oomph! I tried the 168 and 170 MJ. It's still relatively cool and the 170 seems stronger. I still have a "stumble" at about 1/2-2/3 throttle. This occurs in any gear at steady rpm/throttle position. It just burbles/mises in that certain range. When I hammer on it or go for a fast ride, I don't even notice as the revs blow right past it. What do you think? I'm running with the EMP needle in the #5 groove. Should I try #6 or switch to the EMN needle?
Posted April 20, 2001 - 08:57 PM
Try a #172 main jet and REMOVE the main air jet #200. A second plan to get the burble reduced would be to try EMN#4.
How does it compare to your friend's YZ426?
Posted April 23, 2001 - 03:10 PM
I'll try the EMN #4 with the 170 MJ and the #200 MAJ removed. I have'nt had a chance to do side by side comparison with the YZ yet. My "seat of the pants" memory tells me mine is still slower. I'll let you know on the jetting results and subsequent drag race!