YZ Timing and jetting issues......



7 replies to this topic
  • Shane

Posted November 27, 2000 - 04:42 PM

#1

Would like to know what any of you think of the yz timed wr's is it worth the change? do you get more pull? power? Ive got a 2000 WR400 w/White brothers E series sbend with hi-flo header..... I recently put a ekp needle (4th clip position) and jetted to 172 main/45 pilot up until the weather changed .... (its now hovering around 25-40 degrees) the bike just ripped.... noticed lately that iam stalling more and the bike does not seem to "rev" out like it did a few weeks prior (warmer weather) any suggestions? also ... on that yz timing.... Iam considering doing the mod myself... has anyone done this?? any problems or things to watch out for? it seems pretty straight forward.....

thanks!

shane from washington
2000 WR/jetting based on James Deans recomendation/devol guards (Frame/skid/radiator/one industries graphix and seat cover/BBR aluminum sub-frame/pro-tapers/applied triple clamp/steel braided brake lines/white brothers e series sbend with hi-flo header pipe/acerbis handguards/ufo front disc guard/moose rear fender bag/moose front fender bag/ and misc other goodies.........

  • MS

Posted November 27, 2000 - 04:49 PM

#2

Shane:

Im new to this web browser, but I have a 98 WR400, stock jetting and stock timing, however I am currently adjusting my valves and have the cams out to adjust and also thinking about doing the YZ timing. I think it really depends on what type of riding you wish to do with your WR. I currently ride the SETRA enduro schedule with mine and I can tell you that the WR in stock timing is plenty fine for the pull. I have heard that the YZ timing gives it more mid to top pull. Sounds like you are running a little rich with the weather change, pull your plug and take a reading. To make the adjustment to the YZ timing look at the technical section of this web page, it will step you through it. good luck if you decide to change and let us know what characteristics the engine obtains with the timing....I'm going to leave mine stock for now.

MS
shane from washington
2000 WR/jetting based on James Deans recomendation/devol guards (Frame/skid/radiator/one industries graphix and seat cover/BBR aluminum sub-frame/pro-tapers/applied triple clamp/steel braided brake lines/white brothers e series sbend with hi-flo header pipe/acerbis handguards/ufo front disc guard/moose rear fender bag/moose front fender bag/ and misc other goodies......... [/B][/QUOTE]

  • Guest_Guest_*

Posted November 27, 2000 - 05:27 PM

#3

I think it is worth changing the timing. I have a 2000 WR. I had convinced myself that the extra low end power that you get with the retarded timing was worth the loss at the top. I have been experincing plug fouling problems and got sick of messing around with my bike. I want to ride not tinker. I took my bike to a local YZ400 expert and told him to fix it. He set the carb back to original specs, (I had tried every Jet on the site)put in an EK plug (I think it is like a split fire) and adjusted the valves, (I guess the were slightly loose). He also advanced the timing. What a differance. The low end is as good as ever, but the top will pull my arms off. Fourth gear through sand woops I have to back off the gas to get the front wheel down. The 1/4 to full gas must be up by at least a couple of hp. With cold weather setting in I can clean and lube bike to get ready for the next cross country season and not have to worry about the engine!!

  • Heywood

Posted November 27, 2000 - 05:57 PM

#4

I changed to YZ timing and I won't go back. I ride 10% street, 30% moto, and 60% trail and play riding.

At first I did experience some additional stalling, but now that I am use to it, I don't have a problem.

The change was pretty straight forward, I put on a YZ pipe and lost the "octopus" at the same time. I used Clark's jetting suggestions from the Technical page and every thing worked bitchen. Do a search because there is a lot of discussion on this topic.

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  • ande749

Posted November 28, 2000 - 03:59 AM

#5

(its now hovering around 25-40 degrees) the bike just ripped.... noticed lately that iam stalling more and the bike does not seem to "rev" out like it did a few weeks prior (warmer weather) any suggestions?

When weather gets colder, the bike usually runs leaner. Also you could cover the other radiator at least partly. I had same the kind of problems as you and I changed DXM-needle from #4 to #5 and mj from 170 to 175. I also covered left side radiator almost completely.
Ande

  • Shane_In_Washington

Posted November 28, 2000 - 02:42 PM

#6

yeah fordy... i live in nine mile falls washington.... just outside of spokane....
as far as the yz timing mod... will the ekp needle work? with the yz timing or do i need to change out to something else? as far as my current jetting.... am i to rich? or to lean.... some people say colder weather =lean condition.... some say colder weather =rich condition iam still confused as to which way to go with the jetting..... like i said up till a few weeks ago.... with the new ekp needle (which i believe is a yz426 stock needle) i thought i had my bike dialed in to the nuts.... it just ripped i had a grin ear to ear when i got that mod done.... 4th gear wheelies no problem..... went through a brand new michelin in a week! back to the yz timing i was talking to a mechanic at the local yamaha shop (westside yamaha... spokane wa) anyways... he said DO NOT CHANGE TO THE YZ TIMING IT WILL BEND VALVES!!!!he says the cams are different between the two bikes...) to top that off i went out to the other 2 dealers in the area and all those mechanix's said they highly recommend the mod!! what gives?

  • James_Dean

Posted November 28, 2000 - 06:04 PM

#7

Shane,

Go for the YZ timing if you want. Your jetting is getting lean. Try backing out the pilot screw a little (1/4 turn at first). The stalling is typical of lean pilot jetting and slow idle. A bigger pilot #48 and 1 turn on the pilot screw works good especially with the #100 pilot air.

The EKP is a YZ426 needle. There is no reason to go back once it's dialed. In cold weather it may work better with a bigger main.

James

  • MKB

Posted November 28, 2000 - 07:37 PM

#8

If its colder you need richer jetting just the same as when your bike is cold it needs richer jetting to run ie- the choke, which provides more fuel or cuts back the air depending on what bike or carby your using.
The WR provides more fuel.
The reason is that cold air is more dense than warm so it makes your bike run leaner.




 
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