Help me PLEASE!!!!



10 replies to this topic
  • CuLayTur

Posted July 31, 2002 - 08:20 AM

#1

I know the question of jetting these bike is a well discussed topic on this board and I have read the Jetting Q's that in now in book form, but I'm even more confused after stopping in and talking to my local dealer. From my local dealers service shop, I asked them what they do to change the jetting for the altitude out here in Colorado. This is what they say. 170 MJ, 48 pilot, stock needle(DTM) in 5th position and 3 turns on the pilot screw... This seems backward from what I was reading in the Jetting Q's post.. I would think you need to go leaner on gas (smaller pilot,MJ and correct ration of MAJ and PAJ) to compensate for the thin air out here. I've already ordered from SUDCO the adjustable PAS and smaller MAJ.

Do these bikes, in stock form, come from the factory with leaner jetting or richer to pass the emission regulations here?

I have currently a 40 pj, 75 PAJ, 158 MJ and 200 MAJ with the DTM needle in the 4th position and when I ride in the Divide trailsystem (about 9500 ft), I have a really bad off throttle bog that will kill the bike when I snap the throttle open.

This wouldn't be the first time I'm confused about something on this bike.


Thanks Alot for any help,
Curt

  • Dodger

Posted July 31, 2002 - 08:48 AM

#2

Hey CuLatTur;

I'm not going to be a heap of help, but a 170MJ for our riding would be quite a bit to rich, IMHO. My bike came jetted fairly well, so haven't needed to mess with much besides the main, so I don't even know what I'm running for sure. But, I do run a 158MJ for anything over 8,000K, and a 160MJ for around Boulder. Still have the same plug in since last November (crap, now it's going to foul :) ), and only change my main depending upon where I'm going to ride. If you like, I plan on pulling my carb sometime in the next week or so for a full cleaning, and to write down my jetting, feel free to PM me, and I'll share what I'm running.

Late

Dodger :D :D

  • Dave_W

Posted August 01, 2002 - 06:57 AM

#3

Curt,
First of all don't ask the dealers anything about jetting!!!!!
I ran into the same problem earlier this year on my 02 WR426. Luckily I ran into a guy (LarryCO) here on TT, he told me what config he was running. I decided to try the same setup and it works great. (Thanks LarryCO)
38PJ / 65 PAJ (or 3/8 turn out using a PAS instead) / EKP #3 / 150 MJ / 160
MAJ / approx. 1.5 turns on pilot screw. Keep in mind jetting opinions seem to vary be person.
Good Luck,Dave

  • Dave_W

Posted August 01, 2002 - 06:59 AM

#4

Curt,
First of all don't ask the dealers anything about jetting!!!!!
I ran into the same problem earlier this year on my 02 WR426. Luckily I ran into a guy (LarryCO) here on TT, he told me what config he was running. I decided to try the same setup and it works great. (Thanks LarryCO)
38PJ / 65 PAJ (or 3/8 turn out using a PAS instead) / EKP #3 / 150 MJ / 160
MAJ / approx. 1.5 turns on pilot screw. Keep in mind jetting opinions seem to vary be person.
Good Luck,Dave

  • Old_Novice

Posted August 01, 2002 - 07:13 AM

#5

Originally posted by Dave W:
Curt,
First of all don't ask the dealers anything about jetting!!!!!


I second that! The local dealer that "jetted" my buddys YZ for altitude only changed the pilot jet one size (48 to 45). My bike, on the other hand, was set up way to lean, go figure.

It sounds like they are compensating for a rich needle with a leaner jet on each end (PJ & MJ).

I just got all the parts in to try Larry's set up as well as some stuff suggested by both Taffy & JD. This should be an eventfull weekend.

I did get a chance to finallly try my current setup at Aztec. It poped a little on decel, but pulled really well. Here is where I am at at the moment: PJ=42 ,PAJ=75, MJ=165, MAJ=200, DVR 4th position, SJ=65, FS=1.75 turns, Taffy AP mod ~.060

I will be trying a DVP needle next, then Larry's specs. I'll post the results when I have them.

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  • Dan_from_HB

Posted August 01, 2002 - 03:52 PM

#6

Definitely listen to your fellow TT'ers from Colorado. They seem to have it worked out pretty well. Whatever you do, don't listen to the dealer.
Dan

  • Old_Novice

Posted August 01, 2002 - 04:35 PM

#7

Curt, I'll try to keep this short. I tried the DVP needle tonight. With that needle and the setup I mentioned above, the bike pulls really well from mid range on up. It would seem to be a good moto setup, the P straight eliminated my decel poping. Still seems a bit fat in the lower throttle positions,(not as much snap as Taffy might say) though way better than where I started. I then swapped in the LarryCo setup. PJ=38, PAJ=65, MJ=150, MAJ=160, EKP #3, FS 3/4 turn, AP spacer gap reduced to .030. This setup made for dial-a-wheelies. The best off the bottom so far. I think the main jet is a bit lean (and maybe the needle position too)as it does not pull as hard from half throttle up & vibrates a bit in the bars. I'll have to sort this out over the next few days.

Bottom line, lose the DTM. There are two good places to start your tuning adventures here depending on which needle taper you want to play with (E-- or D--). Larry's setup might be just right a little higher up (Rampart) than here in the Springs.

  • CuLayTur

Posted August 02, 2002 - 10:44 AM

#8

Thanks for the great information guys. The bike is now down at Rocky Mountain, getting another problem sorted out. Seems to have developed a really bad knock (not from gas) that is causing me great concern. Doesn't sound like a valve adjustment, but something worse. Also some off my problem's with the jetting fouling the plugs, could come from the fact that I am burning almost
a quart of oil in the last 150 miles. :-(

From everything stated above, I should dump the DTM needle and go to the E-- or DVP® type. I know the WR400 and 426 carbs are different, but I guess the same rules would apply to both. I was just concerned that some of you have the YZ timed bikes, and that might be cause for different jettting that a WR timed bike. Also, when I took the carb apart the last time, I found out I have a 82 SJ... Man these seems huge, compared in the later models that are running a 65 SJ.. I'm starting to believe jetting a bike is not a science but a well respected ART form...

Also I think it's time to de-octopuss that dang carb. It's a mess everytime you need to remove that thing to change the jettings.

Thanks,
Curt

  • CuLayTur

Posted August 02, 2002 - 10:47 AM

#9

Does anybody have any pictures of their de-octopussed carb look like after completed that can be posted? I think I understand what it will look like, but like they say, "One pictures is worth a thousand words"..


Curt

  • Old_Novice

Posted August 02, 2002 - 02:09 PM

#10

Curt, are you sure that was an 82? Mine was 62 stock and I know I have to squint a lot to read most of the numbers on these various jets.

If you would like, I could email you a pic of the carb. Just send me a PM with your email address.

  • tbronc

Posted August 03, 2002 - 01:48 AM

#11

Mine has an 82 also. Who knows why. The dtm needle is probably too rich on the straight for altitude, but it could come in handy if you ever ride down low. (0-3000 or so)




 
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