JD Jetting??


8 replies to this topic
  • Kendawg

Posted December 27, 2006 - 04:37 PM

#1

I know, I know, another jetting question...

Here on TT I have read up on jetting and this is what my plans are/were:

Main jet: 165
Pilot Jet: 48
PAJ: Stock
Leak Jet: 40 with a "Boysen Quick Shot"
Starter Jet: 68
Fuel screw (turns out): 1.75 Zip Tye screw
Needle Model/Clip position: JD red #4

But the JD kit says Im WAYYY off so now Im confused. I ride in Mojave, CA and my ride is a 06 WR450 with all of the free mods and a PMB insert. Elevation is not too high and we only ride when the temps are enjoyable (60 to 90). Any thoughts or opinions would be appreciated

  • clark4131

Posted December 27, 2006 - 06:08 PM

#2

The only thing I see right off the bat is the main. You could stand to go one or two sizes bigger depending on elevation and temp. What's the JD kit saying?...SC

  • Fullbore4

Posted December 27, 2006 - 07:50 PM

#3

Whatever happened to seeing how the bike runs before making jetting changes? Except for the pilot circuit, it is very hard to tune a WR. So here's how to set pilot circuit:

First take 5 minutes and disable the ACV so it doesn't interfere with the pilot jet circuit. Then while the bike is completely warmed up make a fast idle. Turn the zip tye all the way in......if the motor dies, your pilot jet is correct...If there's no change, put in a smaller PJ. Now start 1 turn out....... restart.....now adjust zip tie until the idle is fastest....if your over 2-1/2 turns out total.....put in a bigger PJ and start over. When you have it set, if you want, enable the ACV again.

For needle and main, I find it easiest to see if the motor is breathing hard or missing (lean) or stumbles and feels fat (rich) when accelerating at mid and full throttle. These are hard to tell unless you just try different clip positions/main jets to see which it runs the best with. ie. seeing how short of a run you can get up to 70 mph or something similar.

As far as backfiring on decel, a WR is suppose to do that but not excessively......and besides that only tells if the bike is lean at low throttle, that is when you let off......hence darn near usless indicator.

Reading plug color is decieving for a WR also unless you do it right....such as holding throttle wide open, killing the bike and coasting to a stop with throttle held open and then pulling the plug for a main jet reading, etc.

I admit it has taken me months to get my bike running like I want it to but now it is extremely crisp over full throttle range at about 35 deg F with the current barrage of jets I have in it now. I found Indy's chart invaluable for a starting point but because I have a Powernow installed, I can run with leaner jetting.

Each bike has different mods and is run in different conditions so even if you read until blue in the face, you have to become familiar with how your bike runs and be able to tell subtle differences with jetting....hence I feel sorry for newbies that own the 07 (as hard as it is to change jets)....good luck......out.

  • toyota_mdt_tech

Posted December 27, 2006 - 10:02 PM

#4

I know, I know, another jetting question...

Here on TT I have read up on jetting and this is what my plans are/were:

Main jet: 165
Pilot Jet: 48
PAJ: Stock...


Agree on the 165. I bought the JD kit and it said 170 main, so I did it. Ran rich, good power, but poor economy (no range) so I went down to the 168 and still ran fine, range better. Dropped it to the 165 now, runs great still. Range is much better. It came w ith a 160 stock. I might push it a little further when I'm bored, but content right now with the 165. I am running the blue needle, pos #3, but will change to the red #4 as you are going to do. Seeing if it runs well still, and extends my range.

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  • 05WR450F

Posted December 28, 2006 - 04:27 PM

#5

I know, I know, another jetting question...

Here on TT I have read up on jetting and this is what my plans are/were:

Main jet: 165
Pilot Jet: 48
PAJ: Stock
Leak Jet: 40 with a "Boysen Quick Shot"
Starter Jet: 68
Fuel screw (turns out): 1.75 Zip Tye screw
Needle Model/Clip position: JD red #4

But the JD kit says Im WAYYY off so now Im confused. I ride in Mojave, CA and my ride is a 06 WR450 with all of the free mods and a PMB insert. Elevation is not too high and we only ride when the temps are enjoyable (60 to 90). Any thoughts or opinions would be appreciated



I ride in mojave too. Im running everything you just listed, except I have a Dr. D pipe, but my main jet is a 170. The bike rips!:lol:

  • Kendawg

Posted December 28, 2006 - 05:58 PM

#6

Yes Clark the JD kit calls for a 170 main. I think I will do what toyota_mdt_tech said and drop to a 168. Isnt a bit rich better than a bit lean?

I bought this bike used and Im not exactly sure what jets are in it. I live in Vancouver, WA and fly down to Cali to ride with my brother so I cant just run out to the garage and check. The bike was delivered to him and he said it runs great but pops on decel. Ive told him to just go buy a JD kit and take it to a shop and set it up per my request. When my brother bought the kit he saw that what I wanted and what JD recommends was different. And thats when I got confused. Thanks all for the help.

Hey 05WR450F, Are there any other places besides Spangler Hills and Jawbone that are not too advanced, my brother and I are not pros and we take our boys.

  • 05WR450F

Posted December 28, 2006 - 08:52 PM

#7

Hey 05WR450F, Are there any other places besides Spangler Hills and Jawbone that are not too advanced, my brother and I are not pros and we take our boys.[/QUOTE]

We go to a spot in mojave right thru the town past the "auto zone" on the right side. If you look to your left there are some windmills. They is some pretty good riding there, and it is generally never crowded at all.

  • James_Dean

Posted December 28, 2006 - 09:34 PM

#8

Yes Clark the JD kit calls for a 170 main. I think I will do what toyota_mdt_tech said and drop to a 168. Isnt a bit rich better than a bit lean?

I bought this bike used and Im not exactly sure what jets are in it. I live in Vancouver, WA and fly down to Cali to ride with my brother so I cant just run out to the garage and check. The bike was delivered to him and he said it runs great but pops on decel. Ive told him to just go buy a JD kit and take it to a shop and set it up per my request. When my brother bought the kit he saw that what I wanted and what JD recommends was different. And thats when I got confused. Thanks all for the help.

Hey 05WR450F, Are there any other places besides Spangler Hills and Jawbone that are not too advanced, my brother and I are not pros and we take our boys.



You're running 2 steps smaller main jet, which isn't a major problem. The Red needle and clip position you're using are leaner, but you have a bigger pilot jet to offset these. Overall the jetting is working well because the circuits overlap and there are balancing factors.

James

  • Kendawg

Posted December 29, 2006 - 12:44 AM

#9

So James Dean, If I understand you correctly than what I originally requested will work? and work good? which do you suggest 165 or 168?

Thanks for the input JD. I only get to ride about 4 times a year and I like my bikes ready and perfect when I get there.

If anybody is interested I have my Perfect WR04 for sell!! The bike is ready to go and needs nothing. PM for pics. $4000




 
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