Posted March 14, 2001 - 06:22 AM
I'll preface this by saying I have tried quite a few settings before, my jet parts counter guy links I'm a loon. This has been a learning process for the last year. While other settings have given good results, the following has given the best so far in terms of sheer power that is still useable.
Temp: 50 F
Altitude: 800 ft
Humidity: 48% (could be a little off, this was from a very old baromter)
Terrain: mixture of mud, soft MX track, leaf filled trails, hills, no sand.
Bike: '00 WR400. YZ timed. Stock YZ pipe. WB tapered Ti header. Airbox lid off/thottle stop cut, WB powerfilter. No other engine performance mods. Other stuff than may be of interest: Use castrol 20W/50 oil. Red Line watter wetter.
OK, here's the beef:
Needle: EKP #4
Main: 170 (172 felt no different)
Pilot Jet: 48
Fuel Screw-1.1 turns
Main air jet: #100
All other jets/settings stock (AP and TPS stock)
As a few folks have mentioned, a combo like this gives a nice torquey feel down low and is smooth on the trail. The moment you wick it past 1/4 thottle, it leaps to life. 4th gear wheelies (14/52 gearing) where doable for sure. Very smooth, yet on the verge of peaky power. Slamming the throttle open is not a problem, it doesn't bog at all!
I was using the EKN for a while, and while it felt pretty darn good, it seemed to "overreact" a little too much. Wheelspin seemed to be more of an issue than the EKN.
Since it's a typical slippery spring, I opted to continue to use a little smoother combo. Thre EKN (#4 was really the only position that worked well at all) also seemed to bog a bit when opening the throttle quickly from idle/off-idle.
I hope this helps someone out with a '00 and similar setup. Please note, with WR timing this probably isn't the hot ticket.
On a totally separate note: Under the advice a tire thread a few months back, I tried the Mich S12 front/D755 rear for soft-terrain conditions. The D755 works better than a 756! The S12 was AWESOME! The control and resistance to washing out was superb! I may keep experimenting with rears, but the S12 is a keeper!
Posted March 14, 2001 - 07:26 AM
Thanks for taking the time to share this with everyone. Glad it's working for you too!
Posted March 14, 2001 - 08:08 AM
Sadly, though as the temps/humidity rise to 80+/70%+ the settings may need further leaning for optimal performance, but hopefully not by much.
I may be interested in experimenting with one your trick triple tapers, too. After trying countless combinations of needles/clips/jets,
this is something I have been wondering about. Hook me up!
BTW, Jay R from Cinci says hi (rode with him two weeks ago)-he sold the WR and has a KTM250mxc
Posted March 14, 2001 - 12:17 PM
Posted March 14, 2001 - 08:03 PM
I must say it has never ran better. From start all the way up to WFO it runs 100% better. The power is awesome and on the pavement, 1/4 throttle in 2nd gear sends the front end to the sky!!
I went from totally stock jetting, stock pipe, yz timing and stock wr tank and seat to
pro circuit pipe, yz tank and seat, and EKP #3 #100 Pilot air, #48 pilot and #170 main jet.
Needless to say it was a totally different bike. It was like I was riding a dirt bike again instad of a couch. Power is unreal and I can actually carve turns now.
I didn't get a lot of riding in due to a very bad wreck at the riding spot- yamaha banshee vs. honda xr50-70 head-on. The kid on the xr was very bad off so we took time off from riding to check out what was goin on. It took about 15 min. to get a helicopter in but they kept him in the ambulance for about 15-25 minutes after the chopper got in and I overheard someone say later that he had passed. I kinda shrugged off that scenario but seeing how long they kept him in the ambulance after the chopper got there I thought about it some more. Usually when the chopper gets there they are gone in a few minutes. I remember seeing them put him in the bird but I was so far away all I could see was a sheet. Maybe his injuries were fatal. What a sad day. I wonder what his name was? Sorry to bring it up but I get aggrevated when some cowboy with little or no riding experience goes wide open without regard to his or other peoples safety. I don't know all the facts but normally where we ride I see all kinds of idiots flyin around on 4-wheelers, no helmet or any other gear or riding experience.
I guess we just have to keep an eye out like usual.
Sorry to get off the subject, just had to get it off my chest. Thanks everyone!!
Posted March 16, 2001 - 01:44 PM
Posted March 16, 2001 - 04:00 PM
Yamaha part #5JG-14916-EP is EKP (as shown in the '00 YZ426 shop manual)
If you want another option Sudco at 1-800-998-3529 sells an EMP needle that is brass. Use 1 clip position lower to get the same results, EMP#5 = EKP#4.
[This message has been edited by James Dean (edited 03-16-2001).]
Posted March 20, 2001 - 12:22 AM
I know its off topic.. but I just had to mention..
Posted March 20, 2001 - 03:21 AM
86TT225, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. De-octopussed. Works frame guards and Thumper Rad Guards, Scotts steering damper. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank, IMS seat and number plate. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA, Happy Ramblers MXC.
Posted March 20, 2001 - 11:38 PM