Boit,Hick,Taffy,(paj)?



14 replies to this topic
  • yzf322

Posted May 31, 2002 - 04:23 AM

#1

Hey guys i saw the post for paj in the forum for wr's and i was wondering if i removed the paj what effect will it have. I'm running a 45 pj and according to the specs that i saw im not getting enough air from the paj, im just curious since i don't have any paj to put in as yet. I'm in tennessee and my elev. is 4-500 ft.

  • Hick

Posted May 31, 2002 - 06:31 AM

#2

Opinions and effects will vary, and I have no experience at your elevation, but I would say that with a 45 pilot the stock 100 PAJ should work fine. If you want to try something different total PAJ adjustability is only about $14 away.

Carb Parts 216-524-1599

Air Screw 1014-817-2000
Coil Spring 16052-KM4-0040


Sudco 800-998-3529

Air Screw 021-230
Coil Spring 021-235

(better double check those PNs)

Hope this helps.

  • Jason_in_KC

Posted May 31, 2002 - 07:06 AM

#3

Hey Hick, I am interested in what you are saying here, are these combined parts to make an adjustable PilotAirScrew, thus replacing the PAJ? Similar to the adjustability of the fuel screw on these carbs?? I have been having trouble w/my ELN needle at the initial start up of the day, Taffy advised the 75PAJ w/my 40pj, but would this airscrew/instead of air jet replacement be a viable alternative? Do tell before I commence w/the ordering of jets etc...Thank you. Jason

  • Hick

Posted May 31, 2002 - 11:49 AM

#4

Yes to all three questions Jason.

Below is a table that shows how many turns out corresponds to what PAJ size. Sorry the table is so big, and for this big space below, I tried and tried and couldn't fix it. Won't go by the font size tag for some reason...

<table border>
<tr>
<td align=center><font size=”5”>
<center>Number of turns out 

on air screw </center>
</td>

<td>
<center>Approximately equal 

to this pilot air jet size </center>
</td>
</tr>

<tr>
<td>
<center>1/4 </center>
</td>

<td>
<center>45 </center>
</td>
</tr>

<tr>
<td>
<center>3/8 </center>
</td>

<td>
<center>55 </center>
</td>
</tr>

<tr>
<td>
<center>1/2 </center>
</td>

<td>
<center>65 </center>
</td>
</tr>

<tr>
<td>
<center>5/8 </center>
</td>

<td>
<center>75 </center>
</td>
</tr>

<tr>
<td>
<center>3/4 </center>
</td>

<td>
<center>85 </center>
</td>
</tr>

<tr>
<td>
<center>7/8 </center>
</td>

<td>
<center>95 </center>
</td>
</tr>

<tr>
<td>
<center>1 </center>
</td>

<td>
<center>100 </center>
</td>
</tr>

<tr>
<td>
<center>1 1/8 </center>
</td>

<td>
<center>110 </center>
</td>
</tr>

<tr>
<td>
<center>1 1/4 </center>
</td>

<td>
<center>120 </center>
</td>
</tr>

<tr>
<td>
<center>1 1/2 </center>
</td>

<td>
<center>125 </center>
</td>
</tr>

<tr>
<td>
<center>1 3/4 </center>
</td>

<td>
<center>130 </center>
</td>
</tr>

<tr>
<td>
<center>2 </center>
</td>

<td>
<center>135 </center>
</td>
</tr>

<tr>
<td>
<center>2 1/4 </center>
</td>

<td>
<center>140 </center>
</td>
</tr>

<tr>
<td>
<center>2 1/2 </center>
</td>

<td>
<center>145 </center>
</td>
</tr>

<tr>
<td>
<center>2 3/4 </center>
</td>

<td>
<center>150 </center>
</td>
</tr>

<tr>
<td>
<center>3 </center>
</td>

<td>
<center>155 </center>
</td>
</tr>
</table></center>


Learn more about air jets and all others in the FCR from this Keihin Carb Tuning web page.

[ May 31, 2002: Message edited by: Hick ]

  • Boit

Posted June 02, 2002 - 07:35 PM

#5

To tell you the truth, I really don't know the answer. Hick and Taffy were excellent choices as to who to ask for advice. Personally, I was able to dial in my carb using the Factory R&D accelerator plate along with VP MR2 fuel and crisp jetting. Yes, it DID take some experimentation to get it all dialed in, but it was well worth the effort. The knowledge I gained is invaluable. Don't be afraid to try different settings. Simply make one-step changes and keep accurate written records. As you go, you should see a trend as to what works and what doesn't. . . not to mention the seat-of-the-pants results. In the end, what jetting works for me may not work for anyone else. What I have found to work well when trying to dial in the jetting is work from a rich setting and then work my way in small increments to leaner jets. I always install a jet and then ride for at least a half hour before I determine my next step. All I can say is try to have an open mind and be sensitive to how your engine performs. Learn what lean is like and what rich is like. With so many combinations, resist the urge to make more than one change per test. If you make two changes and the engine runs worse, how do you know which change made it run worse? Be methodic and make ONE change per test.

  • Jason_in_KC

Posted June 03, 2002 - 10:34 AM

#6

Thanks Hick, your part #'s were spot on, just got off the phone w/a "brit" from Sudco..almost asked if his call sign was Taffy..hehe
The Pilot Air Screw and corresponding spring are on their way to my house via UPS...hopefully in a few days I will have this in and running good w/the mighty ELN needle...woohoo!
Total $12.34 w/o shipping..anyone wanting to tune this machine should probably have one of these and a Kouba tool..hands down! Thanks again Hick for the part #'s and Taffy for the jetting info. Jason

  • Shawn_Mc

Posted June 03, 2002 - 10:45 AM

#7

JasonKC click that link to Tuning the FCR and print that document. Thats a plain ole "bitchen" piece of work. Im gonna go nuts. That guy is a smart son of a gun.

Ego, youd like that too, go check it out.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Jason_in_KC

Posted June 04, 2002 - 02:42 AM

#8

Agreed Shawn, that is a good piece of work, explains alot about just how multi-tuneable this carb is..very good read. The guy said something to the effect of "you are not gonna get the PAJ change right on the 1st,2nd, or even 3rd try, so you might as well get an adjustable PAS"..Hick posted the part #'s from that article and the Sudco rep went right to them and described the combo w/o my asking first, I am confident this will allow me to dial in the cold starting issues I have had w/the ELN needle..if it does, look out, that needle rocks! :)

  • Shawn_Mc

Posted June 04, 2002 - 06:58 AM

#9

Just remember that the PAJ changes the ENTIRE range of the jetting. So you may have so more testing to do.

  • Jason_in_KC

Posted June 04, 2002 - 08:10 AM

#10

That's cool, thanks for the warning Shawn, my biggest worry is with the intial cold start of the day..if I can get past that, the bike runs fine and I know what rich/lean conditions "feel" like already. I had that ELN running w/a 40p,162main, it hit hard in the midrange but signed off soon after.. I have some specs from Taffy that I will try..but again, once running..whew, it pulls hard! I am pumped to start in on this new jetting project, having the adjustable PAS will be cool. I have owned my 01' since Oct of 00' and so far this needle has netted the biggest seat of the pants results since ownership..makes you realize how important jetting is when you feel positive results.

  • Taffy

Posted June 05, 2002 - 11:49 AM

#11

picked up this thread late lads so it looks like all the good work is done.

i would just say that IMHO the needle straight and starter jet are what get your bike started.

i know that you're on out-and-out racers but even you need choke.

this tells us heeps and heeps about the jetting. seriously!

if you have it on choke for less than 30 seconds before it eight-strokes = get a smaller start jet (I.E. less 5 will do). the needle straight is the other.

without killing the subject i would say that we sea level folk need only an M needle and by the time you're at 10,000 ft like Hick it's a P or even a Q. i feel the Q is extreme but not being there i won't argue.

what is for sure is that you can pick your needle straights to go in between so that 4-5000 ft might be an N or P.

you should always need choke to start. if you don't and you have your own madcap scheme then fine. the trouble is that this will change as you jet down.

when you've arrived YOU WILL need the choke!

Taffy

  • Jason_in_KC

Posted June 06, 2002 - 03:58 AM

#12

Good stuff Taffy, boy do we need computer interpreters though..hehe
The guy that started this thread is at 4-500ft, not 4-5000, essentially he and I are about 300ft difference in sea level, he and I should net similar results being so close to sea level and having similar temps/humidity readings.
I'll tell you this, the day my bike wouldn't start w/the ELN #3 and 40pj the plug was dry after 15-20kicks, anyone that has owned one of these bike knows that after at least 10, that plug is usually wet. This is what led me to believe that it was too much air and not enough fuel, but weird thing is, it was warmer outside and very humid? W/the PAS on its way, I hope to dial this thing in for easy cold starts, the rest is simple seat of the pants testing!
Taffy, when you say "starter jet" are meaning Pilot? BTW, I always use the choke at initial start up for the day. Also, when you suggested "M" needle..is that the EMM? Many thanks, Jason

  • Hick

Posted June 06, 2002 - 05:46 AM

#13

Originally posted by Jason in KC:
Good stuff Taffy, boy do we need computer interpreters though..hehe

Taffy, when you say "starter jet" are meaning Pilot? BTW, I always use the choke at initial start up for the day. Also, when you suggested "M" needle..is that the EMM? Many thanks, Jason


He means starter jet, a jet that feeds the choke circuit.

By “M” needle he means one with a richer straight diameter like an EJM, this would be two sizes richer than a stock EJP. EMM

Originally posted by Taffy:
if you have it on choke for less than 30 seconds before it eight-strokes = get a smaller start jet (I.E. less 5 will do). the needle straight is the other.

without killing the subject i would say that we sea level folk need only an M needle and by the time you're at 10,000 ft like Hick it's a P or even a Q. i feel the Q is extreme but not being there i won't argue.


TRANSLATION:

“If you start your bike cold and it won’t run with the choke for 30 seconds you need a smaller start jet. The needle straight diameter is the other factor that affects how the bike starts.”

“At the risk of boring all you stupid Yanks, I would like to opine that for those at sea level, like myself, a needle with an M-sized straight diameter works well. By the time you get to much higher elevations like that oxygen-deprived Hick you may prefer a P or even (gasp!) a Q-sized straight diameter. I personally think Hick is off his rocker for running a Q but I’m tired of arguing about it.”

To translate the rest of Taff’s post cut and paste HERE.

:)

  • Boit

Posted June 06, 2002 - 09:24 PM

#14

Now THAT was funny!... :)

  • neWRiver

Posted June 06, 2002 - 09:36 PM

#15

Scary, I actually understood every bit of Taffy's post without the translation.... :)

I may have to go back and reread some of his earlier posts. I have a feeling I'll learn something that I missed the first time. :D





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