Rehashing the ACV Question


20 replies to this topic
  • clark4131

Posted March 21, 2006 - 05:13 PM

#1

Just out of boredom, I was researching the ACV thing and decided to try it out just for :thumbsup: & grins. It seems that most people who have done the mod have blocked the valve and ports by flipping the diaphragm and/or cutting a piece of inner tube, etc. to block the O-ring, which then requires use of a 100 PAJ to compensate. My question is, what about making a spacer to take the place of the spring so the diaphragm is then unaffected by the vacuum? Then, you could leave both your PJ and PAJ alone, correct? I was trying to discern if there were more benefits with one method over another. Furthermore, what are the factors to consider when doing it in regard to YZ and WR timing? I realize this topic has been around forever, but I was curious as to the effect of blocking the valve open, rather than closed. I know, I know, I need another hobby, but it isn't SCUBA season yet and I hate diving in my dry suit if I don't have to...SC

  • odonnks

Posted March 21, 2006 - 05:21 PM

#2

I have no answers but I'd like to know too. I've been wnating to try some things with the ACV too.

  • Matty05

Posted March 22, 2006 - 03:29 PM

#3

Let me know how you go......... Just use a longer spring or stretch the one you got!

  • bg10459

Posted March 22, 2006 - 04:38 PM

#4

Clark, you are correct. If you block the valve open you can stick with your PJ and PAJ, but this is essentially the same as just blocking the vacuum port (see method 2). If you block it closed, you richen the pilot circuit because you cut the air to the circuit in half. This requires leaning it back out with the larger PAJ and/or a smaller PJ.
I can't see why the different timing would matter (ignition timing, not cam timing, right?)

SEE HERE

  • snakesausage

Posted March 22, 2006 - 05:53 PM

#5

I just went through a clogged ACV circuit episode and I think that if you are planning to do anything, in my opinion, the best course of action is to totally disable the circuit and jet like the YZ. The clogged ACV caused my scooter to run really rich even with the fuel screw closed and ended up fouling a plug before I figured out what was going on.

  • TARFELE

Posted March 22, 2006 - 07:19 PM

#6

This is just my personal opinion but shouldnt you be installing the Rekluse so you can give me the low down on that! I need a full report!

And no comments about the pipe!

  • clark4131

Posted March 23, 2006 - 12:15 AM

#7

Clark, you are correct. If you block the valve open you can stick with your PJ and PAJ, but this is essentially the same as just blocking the vacuum port (see method 2). If you block it closed, you richen the pilot circuit because you cut the air to the circuit in half. This requires leaning it back out with the larger PAJ and/or a smaller PJ.
I can't see why the different timing would matter (ignition timing, not cam timing, right?)

SEE HERE


It was much easier to cut a little spacer to fit in place of the spring than to cut something to block the O-ring and diaphragm, then remove my carb to change my PJ and my PAJ. By fixing it in the open position, I changed one thing instead of four in about 3 minutes...SC

  • clark4131

Posted March 23, 2006 - 12:16 AM

#8

This is just my personal opinion but shouldnt you be installing the Rekluse so you can give me the low down on that! I need a full report!

And no comments about the pipe!


Lots of snow, very cold, sinus infection and zero time. Patience Gertrude! :thumbsup: :thumbsup: ...SC

  • bg10459

Posted March 23, 2006 - 06:04 AM

#9

It was much easier to cut a little spacer to fit in place of the spring than to cut something to block the O-ring and diaphragm, then remove my carb to change my PJ and my PAJ. By fixing it in the open position, I changed one thing instead of four in about 3 minutes...SC

By blocking the vacuum port, you prevent the diaphragm from moving and rely on the spring pressure to keep the valve open. By putting in the spacer you keep the diaphragm from moving but you have blocked the valve open. In either case, you can keep the same PJ and PAJ. It's only when you close the ACV (like flipping or removing the diaphragm) that you have change your PJ and PAJ.

  • TARFELE

Posted March 23, 2006 - 06:20 AM

#10

Lots of snow, very cold, sinus infection and zero time. Patience Gertrude! :thumbsup: :thumbsup: ...SC



EXCUSES! EXCUSES! The only one that I give to you is the Sinus infection, that sucks!!

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

Posted March 23, 2006 - 06:02 PM

#11

Soooo...:thumbsup:
Anyone done it (blocked the vacuum) yet and can report back??
Or as Clark says, space it open.
Thanks, looking into this myself and dont want to change the PAJ.
:thumbsup:

  • Matty05

Posted March 23, 2006 - 09:48 PM

#12

Soooo...:thumbsup:
Anyone done it (blocked the vacuum) yet and can report back??
Or as Clark says, space it open.
Thanks, looking into this myself and dont want to change the PAJ.
:thumbsup:

I did do it, I had a few other carb issues that are now fixed, so I will have to try it again.

From what I discovered, it did seem to go better and felt alot more crisp and lively.

I have a 40 pilot jet in my garage, just might need to "borrow" mates 100PAJ.

  • OneToGo

Posted March 24, 2006 - 02:19 AM

#13

I have a 40 pilot jet in my garage, just might need to "borrow" mates 100PAJ.


I assume for this you "block" the ACV by inverting (flipping in burger speak..) the diaphram also block the inside the O-ring :thumbsup:

Matty, is the #40 pilot a match to the #100 PAJ.
I think the YZ runs a 42 (which I have JIC)
If I can get a #100 PAJ I'll try it... :confused:
Let us know how you get on
:thumbsup:

  • Matty05

Posted March 25, 2006 - 05:07 PM

#14

I assume for this you "block" the ACV by inverting (flipping in burger speak..) the diaphram also block the inside the O-ring :thumbsup:

Matty, is the #40 pilot a match to the #100 PAJ.
I think the YZ runs a 42 (which I have JIC)
If I can get a #100 PAJ I'll try it... :confused:
Let us know how you get on
:thumbsup:

Yes thats how you block ACV

I think the YZ does run a 42 PJ (match for 100 PAJ on stock YZF), but I use a 45 PJ now (most use 48), so a 40 PJ should be right for me.

  • 06WR450FSM

Posted March 26, 2006 - 02:22 PM

#15

Does exhaust popping during deceleration increase significantly after disabling the ACV, since this is its purpose?

What kind of spacer works well to keep the valve open? I'd like to try this approach first to avoid rejetting.

Pics would be great!

  • clark4131

Posted March 26, 2006 - 02:40 PM

#16

I used a 5/16" cylindrical nylon spacer from Home Depot cut down to about 1/4" in length with my Dremel...SC

  • OneToGo

Posted March 26, 2006 - 07:23 PM

#17

Does exhaust popping during deceleration increase significantly after disabling the ACV, since this is its purpose?

What kind of spacer works well to keep the valve open? I'd like to try this approach first to avoid rejetting.

Pics would be great!


Dose the spacer method IMPROVE throttle response/ performance?

I know the ACV richens for decel, So..

Does it affect the transition from sudden closed throttle decel to quick open throttle acelleration - keeping the mixture artificially enriched? Just asking!

That is why I thought blocking its affect would be better (a la YZ).

Thoughts?

  • 06WR450FSM

Posted March 26, 2006 - 10:22 PM

#18

I used a 5/16" cylindrical nylon spacer from Home Depot cut down to about 1/4" in length with my Dremel...SC


Thank God for dremels! That tool has made so many repairs and mods possible.. :thumbsup:

  • bg10459

Posted March 27, 2006 - 08:16 PM

#19

That is why I thought blocking its affect would be better (a la YZ).

Thoughts?

Blocking the ACV as Clark has done keeps the extra passage open as it is during normal operation. It normally closes upon decel because the vacuum signal increases and pulls the diaphragm against spring pressure. This richens the circuit temporarily by cutting half the air to the circuit. If you want a YZ like setup you have to flip the diaphragm to keep the valve closed, but your pilot circuit will then be way too rich, so you need to lean it out with a bigger PAJ and smaller PJ. Either way disables the ACV (disables richening of the pilot on decel), you just need to tune the pilot circuit accordingly.

  • OneToGo

Posted March 27, 2006 - 08:40 PM

#20

Blocking the ACV as Clark has done keeps the extra passage open as it is during normal operation. It normally closes upon decel because the vacuum signal increases and pulls the diaphragm against spring pressure. This richens the circuit temporarily by cutting half the air to the circuit. If you want a YZ like setup you have to flip the diaphragm to keep the valve closed, but your pilot circuit will then be way too rich, so you need to lean it out with a bigger PAJ and smaller PJ. Either way disables the ACV (disables richening of the pilot on decel), you just need to tune the pilot circuit accordingly.



Thanks very much, I sort figured it out from FAQ and previous threads - Just wanted to know Does it help - I'll try it anyway next weekend just for kicks...

Cheers
Thanks for the responses - even though not my thread :thumbsup: ME

Colin :thumbsup:




 
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