NCVS vs. NCVQ


12 replies to this topic
  • Krannie McKranface

Posted January 31, 2014 - 12:31 PM

#1

NCVQ / 4th clip down, is working better, on my bike.

 

The small barely opened partial-throttle opening flat spot is all nearly gone.

 

2.765 to 2.745 diameter (richer)

 

That, and re-calibrating my TPS to actual closed throttle (slide at the bottom, not slide at idle position) made an improvement too. 

 

Which change did what exactly?  The world will never know, cause I always do too many changes at once.


Edited by TheKoolAidMadeMeSick, January 31, 2014 - 12:34 PM.


  • GuyGraham

Posted February 01, 2014 - 05:14 AM

#2


2.765 to 2.745 diameter (richer)

 

 

You leaned out your 0 - 1/8 throttle mixture, because the bigger diameter needle is filling the the needle jet hole more and hence letting in less fuel.

 

Flat spot off idle is usually over rich condition causing a bog

Have you checked your float height?


Edited by GuyGraham, February 01, 2014 - 05:14 AM.


  • Krannie McKranface

Posted February 01, 2014 - 06:50 AM

#3

  I went to a smaller diameter needle: from S to Q

  I had a lean-pop at partial throttle.

  I also re-calibrated my TPS with the closed throttle actually being closed all the way (no idle) .

 

No, I have not checked my float height because I DON'T WANT TO TAKE THAT DAMN CARB OUT AGAIN UNTIL I HAVE TO!

I'm sure it's high....

 

Needle changes are easy....

 

The carb has been in and out 16 times in the last 12 mo.....



  • stevethe

Posted February 01, 2014 - 07:23 AM

#4

  I went to a smaller diameter needle: from S to Q

  I had a lean-pop at partial throttle.

  I also re-calibrated my TPS with the closed throttle actually being closed all the way (no idle) .

 

No, I have not checked my float height because I DON'T WANT TO TAKE THAT DAMN CARB OUT AGAIN UNTIL I HAVE TO!

I'm sure it's high....

 

Needle changes are easy....

 

The carb has been in and out 16 times in the last 12 mo.....

 

In and out 16 times that's a job !

 

I have been running either the gytr needle with the WR carb or with the YZ carb the NFLR. I think there is a difference in the needle jet on the two carbs.



  • grayracer513

Posted February 01, 2014 - 10:34 AM

#5

I think there is a difference in the needle jet on the two carbs.


And that's not the only thing.



  • KennyMc

Posted February 01, 2014 - 11:43 PM

#6

 

The carb has been in and out 16 times in the last 12 mo.....

Hmmm, mines been out..............................once :p

 

:awww: Hey Bill :smirk:

 

Of course, it did look like this during my overhaul

post-112655-0-67276800-1391327018.jpg

Carb.jpg


Edited by KennyMc, February 01, 2014 - 11:44 PM.


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  • Krannie McKranface

Posted February 02, 2014 - 07:06 AM

#7

Hmmm, mines been out..............................once :p

 

:awww: Hey Bill :smirk:

 

Of course, it did look like this during my overhaul

post-112655-0-67276800-1391327018.jpg

attachicon.gifCarb.jpg

 

 

Yeah they still talk about 'kens carb' at the shop now and then......



  • Krannie McKranface

Posted February 02, 2014 - 07:07 AM

#8

Well, the needle change solved one thing, and caused others.

 

I am going to try the standard 2006 YZ450F needle next, NFLR.

Totally shooting in the dark now.

 

Aren't carbs fun?


Edited by TheKoolAidMadeMeSick, February 02, 2014 - 07:10 AM.


  • Krannie McKranface

Posted February 03, 2014 - 01:51 PM

#9

BETTER on the street. 

 

Only the dirt will tell. 



  • stevethe

Posted February 04, 2014 - 10:43 AM

#10

Well, the needle change solved one thing, and caused others.

 

I am going to try the standard 2006 YZ450F needle next, NFLR.

Totally shooting in the dark now.

 

Aren't carbs fun?

 

If your still running an unknown needle jet shouldn't you try a brand new drilled one from zipty. Either the drilled YZ needle jet with the NFLR or the WR with GYTR needle or other.

 

You don't have to pull off the carb. :@)



  • Krannie McKranface

Posted February 04, 2014 - 11:48 AM

#11

I already have the perforated emulsion tube in there, which is the main reason for needing to go leaner on the needle, I believe.

 

You say Zipty sells them now?

 

I had to pull off the carb so many times because there was a blockage in the main air jet that was giving me fits. It was a small piece of rubber....almost like someone tried to block it off under the jet....and I found the same kind of plug on the ACV passages. What a moron the PO was.

 

It runs fine even with the wrong needle, but I can tell it's rich, and the power band is peak-ier with the YZ cams, so I need all the help I can get below the peak power.



  • stevethe

Posted February 04, 2014 - 01:00 PM

#12

I think Zipty drills out factory needle jets. So the parts would be good. I have bought them from him and he does the hole mod also.

 

Remember the hot cams are fairly peaky if you are running them.



  • Krannie McKranface

Posted February 04, 2014 - 01:14 PM

#13

I think Zipty drills out factory needle jets. So the parts would be good. I have bought them from him and he does the hole mod also.

 

Remember the hot cams are fairly peaky if you are running them.

 

Well, the leaner needle did the trick. It will pull in just about any gear with the throttle just barely cracked, if you want. 

It actually smooths out the transition to the peak power when using partial throttle.

 

Yamaha used to sell that perforated needle jet for the first two years of WR250. If you order that part number now, it comes like the stock 450: no holes.

 

I also tried the 'Projet' version, but it SUCKED.






 
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