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Which needle in PWK38 airstriker? '00 cr250 woodsbike.

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Hi guys, 

My 2000 cr250r is almost ready. I converted it from OEM to a woodsbike.

I'm fiddling with the carb setup to get the bike handling to my likings. 

First of all the setup:

Suzuki NECJ needle, clip on 4th (a NOZH was in when I bought it)

45 pilot

172 main

1.75t out on as

#7 slide

OEM pipe and silencer (fresh packing)

12oz fww

Boyesen power reeds in good condition

New topend with 13h on it

New crankseals to be sure

Sealevel, around 12 degrees Celsius (50F) right now.

Bike came with a NOZH needle which was way too rich for woodsriding and the bike smoked all the time riding tight singletracks. I swapped it out with a Suzuki NECJ needle which I read good things about. From what I can feel and hear, this needle seems a little bit too lean on the bottom, because when cold started, the bike bogs a few seconds when turning the throttle, but after 4-5 seconds it's ok. When I ride at 1/8th - 2/8th throttle and crack the gas open, it sputters somewhat (with smoke) and than revs up good (rich?), I'm a little confused here...Rev it up in one time there are no sputters or smoke.The sparkplug is chocolate brown, so the MJ maybe is a little bit on the rich side.

So...I read some good stories about the Suzuki RM needles and I think these are the most suitable for my type of riding. Question is...which one? Stick with the NECJ or get a NEDJ / NECW?

20170319_105819.jpg

20170317_122616.jpg

Edited by Daniello

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Here are my thoughts.  My favorite PWK needles are the Yamaha N3CW and N3EJ needles, and the Suzuki N3WJ needle.  My very favorite is the N3WJ needle because it is so crisp and clean and seems to give the bike the ability to rev forever.  With the Yamaha needles you will want to start with a 178 main and a 45 pilot with the needle clip in the 4th position (for the EJ needle) and in the 3rd clip position with the CW needle.  You can use the #7 or #8 slide with the CW and WJ needles but only the #7 slide with the EJ needle.  The Suzuki needle requires leaner jetting on the main and pilot, you will want to start with the 175 or 172 main with that needle with a 42 pilot.  Air screw will start at 1.5 turns out to be adjusted from there.  All of these settings are starting points and will probably need fine tuned for your application. 

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9 hours ago, frdbtr said:

Here are my thoughts.  My favorite PWK needles are the Yamaha N3CW and N3EJ needles, and the Suzuki N3WJ needle.  My very favorite is the N3WJ needle because it is so crisp and clean and seems to give the bike the ability to rev forever.  With the Yamaha needles you will want to start with a 178 main and a 45 pilot with the needle clip in the 4th position (for the EJ needle) and in the 3rd clip position with the CW needle.  You can use the #7 or #8 slide with the CW and WJ needles but only the #7 slide with the EJ needle.  The Suzuki needle requires leaner jetting on the main and pilot, you will want to start with the 175 or 172 main with that needle with a 42 pilot.  Air screw will start at 1.5 turns out to be adjusted from there.  All of these settings are starting points and will probably need fine tuned for your application. 

Ok, thanks for the input.

For what type of riding you use these needles?

It's a little hard to choose which needle to get...Because I found this topic over here on TT:

The Yami guys have a discussion over here and the gros of them like the triple taper Suzuki needles better than the Yamaha duel taper needles.

 

 

Edited by Daniello

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I can't disagree with them since my all time favorite needle is a Suzuki needle.  I wasn't able to use the NE series of Suzuki needles even though I loved the power delivery of them because my bikes ran too lean off the bottom with them.  When I found the N3WJ (both Kawasaki and Suzuki use this needle) it solved that and kept the other characteristics of the NE Suzuki needles I had tried. 

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Did you try richer needles than the NECJ?

The 1 clip richer NECW?

 

Because the N3WJ has the same straightsectiondiameter of 2.745mm you would assume that there should be no different of bottom.

The NECW instead has a 2.735mm starting diameter which is a little bit richer of bottom...

 

Needlecodes_zps7832d07c.jpg

Edited by Daniello

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I tried the NECW and NEDW needles. both would run on idle and surge when letting off the gas.  I think it has something to do with the overall tapers of the needles that fixed my issue and not just the straight section. I'm not a jetting expert.  I did all my needle testing under the advice of RTV who, IMO, is the best PWK tuner on this site.  He made recommendations for me and I experimented until I found the combo that worked best for me.

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11 minutes ago, frdbtr said:

By the way, your bike looks really nice.

Thank you :)

Can you explain 'run on idle and surge when letting off the gas' 

About a year or 2 back I got good advice from CamP and H4L here on the forum...But that was advice for a PWK swap on my '04 CR250... ended up using a CEJ or CCJ singletaper needle back than. Bike ran good than, but used a little bit more fuel if I recall. Don't know if these also work on my '00 model. But honestly I like to try and find the best Suzuki triole taper needle for the bike this time.

Back on the Suzuki needles...

Edited by Daniello

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29 minutes ago, Daniello said:

Thank you :)

Can you explain 'run on idle and surge when letting off the gas' 

About a year or 2 back I got good advice from CamP and H4L here on the forum...But that was advice for a PWK swap on my '04 CR250... ended up using a CEJ or CCJ singletaper needle back than. Bike ran good than, but used a little bit more fuel if I recall. Don't know if these also work on my '00 model. But honestly I like to try and find the best Suzuki triole taper needle for the bike this time.

Back on the Suzuki needles...

I tried the CEJ needle and it is a good needle but I didn't like the power delivery as much as the JD jetting needles I was using at the time so I went back to them.  It wasn't until I started having PM conversations with RTV that I went to the Yamaha and Suzuki OEM needles and I haven't regretted it. A run on idle is when the bike doesn't idle down normally but keeps a higher rpm than it should after coming off of a full throttle run.  The surging sounds like "thrum, thrum, thrum" when it is coming down from a full throttle situation.  I found out through trial and error that both were because the bike was too lean in the lower throttle positions when that happened.   All of the PWK needles will work in your 00 CR, you just need to find the one that works best for you.  I know a lot of guys like the NECW and DW needles and a lot of guys are very happy with the NECH needle as well.  I loved everything about them with the exception that it was too lean off the bottom for me which is why I love the N3WJ needle which works perfectly for me. 

Edited by frdbtr

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Just to give you an example of what happened when I went to the N3WJ needle, I have an 03 and an 06 cr250.  my son rides the 03 mostly and loves it.  He mostly scoffs at my tinkering with jetting thinking I am wasting both of our riding time but when I put the N3WJ needle in the 03 and he took it for a test ride, he came back shaking his head saying "that thing revs forever now". Needless to say he loved it.  It may or may not be the needle for you, I was just offering my opinion on what I have liked.  :)

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Ok, now I understand what you mean.

I must say....I don't have that problem with the NECJ needle...It just bogs when  you start the bike up when cold and than blip the throttle. 

And when I ride some long straight trails fwot it nicely comes back to its idle... With a very minor ping ping ping in between fwot and fully close throttle from 5th gear to say 2nd which I believe indicates a little lean condition??? Why the 3 questionsigns? Somewhere over here I also read that a rich setting can cause this...And the sparkplug color is chocolate brown...Which is a tad too dark if you ask me...Hmm.

Maybe I'll just give the 1 clip richer NECW needle a try and if that doesn't do it I'll try the N3WJ ;)

Thanks for the input!

Others who want to kick in?

Edited by Daniello
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We have had cr250's for a long time. My son's favorite on his 2000 (equipped with a 2001 cylinder) is the same needle Honda sent stock in 1999.   He does single track a lot,   larger tank,  flywheel weight etc.  He is pretty diligent about float levels (Aircraft mechanic and professional pilot).   It just suits him.  We run 20-1 mixes and his is Klotz with avgas (something he has lots of).   I like the above yamaha choices for my yz250,  he has tried my choices in his bike,  but I have yet to try his.   from the notes here that it is a r1370dka.   2 cents. 

If  you really want a trail oriented cylinder,  consider the 99 cylinder as well. 

 

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3 hours ago, Daniello said:

Did you try richer needles than the NECJ?

The 1 clip richer NECW?

You have that backwards, the NEC part is same but you should know W represents I . The last letter in the sequence represents the starting diameter of the needle A being richest and getting Leaner as you get farther down the alphabit.

 

 

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22 minutes ago, Daniello said:

Ok thanks.

20:1 is much leaner than what I'm running.

I mix at 40:1 which makes my mixture richer. I mix Castrol Power RS 2Stroke with 95 pumpgas.

Thanks for the input.

When I give jetting specs I like to tell what else we are doing with them.   One of his friends runs the same needle different cylinder (96)  and is happy with 50-1 Ams.  

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Ok thanks.
20:1 is much leaner than what I'm running.
I mix at 40:1 which makes my mixture richer. I mix Castrol Power RS 2Stroke with 95 pumpgas.
Thanks for the input.

You have the rich and lean part backwards but I know what your talking about.
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ya your right , dont know what i was thinking.

Edited by peaceofwork
change

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On 3/20/2017 at 9:09 AM, Daniello said:

Hi guys, 

My 2000 cr250r is almost ready. I converted it from OEM to a woodsbike.

I'm fiddling with the carb setup to get the bike handling to my likings. 

First of all the setup:

Suzuki NECJ needle, clip on 4th (a NOZH was in when I bought it)

45 pilot

172 main

1.75t out on as

#7 slide

OEM pipe and silencer (fresh packing)

12oz fww

Boyesen power reeds in good condition

New topend with 13h on it

New crankseals to be sure

Sealevel, around 12 degrees Celsius (50F) right now.

 I swapped it out with a Suzuki NECJ needle which I read good things about. From what I can feel and hear, this needle seems a little bit too lean on the bottom, because when cold started, the bike bogs a few seconds when turning the throttle, but after 4-5 seconds it's ok. When I ride at 1/8th - 2/8th throttle and crack the gas open, it sputters some

20170319_105819.jpg

20170317_122616.jpg

1/8 -2/8 opening probably would not be the last letter in NECJ, wouldnt that part of the throttle opening be (C) the second to the end letters control area? possibly the 45 pilot is a size to big and the motor is just loading up and then when you wick the gas it blubbers a second untill it clears its self out , possibly a 42 pilot and the air screw set at about 1/2 to 3/4 of a turn might be worth a try?

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2 hours ago, Brock Blubaugh said:


You have the rich and lean part backwards but I know what your talking about.

If you were aiming at the OP,  he had it right as far as fuel air ratios,   which is how I took it.  

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