I am so confused!



3 replies to this topic
  • Desertbob

Posted March 09, 2001 - 10:58 PM

#1

First let me say that I enjoy all of the posts on Thumpertalk. I am looking for some tuning hints and have found that there is just too much information to sift through to come up with "ball park" settings for my bike. The bike in question is a 2000 WR400F (WR Timing). I have a Vortip and the airbox cover removed. I am running a 45 Pilot Jet (2.5 turns), Stock Needle with stock setting (#3), and a 170 Main Jet. I ride in the So Cal desert and in the Gorman area. The elevation is probably 2000 - 5000ft. I race at the Novice Level in D37 Desert events. My bike currently runs very clean. I seem to have a very soft, smooth but flat power delivery until the upper revs then the bike pulls pretty hard. Going to the larger pilot helped starting and really smoothed out the slow to mid transition glitch.

My goal is to have a smooth but torquey powerband in the low to mid range with roughly the same top end pull (I would give up top end for low end). I don't want a wheelie king or a motocross explosive powerband as I like to make up time in the single track and the slow approach hills and cliffs so common in the areas I ride. I like to use the throttle instead of the speed to get up hills if I can.

What are your thoughts on my performance goals. BTW: I like the quiet of the Vortip and imagine that the YZ timing would be a bit explosive for me (I seem to see lots of YZ's stalled or spun out in the tight, rocky stuff).


------------------
Proud Member of Racers Under the Son (www.ruts.org)& District 37 Desert

98.5 Dodge 2500 24v Cummins 4x4
00 Yamaha WR400
99 Yamaha PW80
99 Terry Fifth Wheel

[This message has been edited by Desertbob (edited 03-09-2001).]

[This message has been edited by Desertbob (edited 03-09-2001).]

  • James_Dean

Posted March 09, 2001 - 03:24 PM

#2

Desertbob,

A fair question-

There is a new carb option that I would like to suggest. It is from the YZ250F. The needle choice is a slight variation on the EKP that came in the '00 YZ426. This will be a minimal change aimed at your WR timing and novice level.

#45 pilot, 1.5 - 2 turns (YES, turn it back in a little)
ELP needle, clip #4 (P/N- 5NL1-14916-EP, from YZ250F)
#170 main

There are lots of options, but this should be a clean running, smooth, nice torque but not flat power delivery. This is very close to what I ran before switching to YZ timing. Airbox cover off, shortened throttle stop, Vortip (or?), WR timing, stock air jets.

To clarify (or confuse :) )EJP,EKP,ELP,EMP carb needles are all the same profile but 1/2 clip apart in the taper position. ELP#4 is the same as EJP#3, although the tip of the needle ends up .9mm shorter because is sits higher.

James

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  • PMAUST

Posted March 09, 2001 - 11:46 PM

#3

Bob, I got my 00WR400 last summer. I have been taking a slow approach to customizing it until I could get myself dialed in a little more. I took several years off from riding. The first thing I would try which is relatively cheap and easy is to lower your gearing. The cheapest way is to replace the stock primary gear to 13. Stock is 14. This is probably about equivalent to 3 teeth more on the rear sprocket. If you like what that does for you but it seems like a little much try putting the stock primary back and replacing the rear sprocket(adding two teeth). The down side of replacing the rear sprocket is that you may have to buy a new chain. My plan is to have two sets of sprockets with a matching chain for each. One set would be for the really tight technical stuff the other more more open desert riding. I haven't ridden Gorman for many years. I have a lot of fond memories of it(like the time I almost got bit in the butt by a rattle snake!) :)

  • Taffy

Posted March 09, 2001 - 11:58 PM

#4

desertbob

i think you should fit a 'D' needle. the power delivery is far softer.

Taffy




 
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