Strange Carb syncing fun

[wolfman]

Done it before. ?Did it again after reading here (thanks) to disconnect the YICS box and plug the vacuum hoses for it. (and because the bike still did not "feel" right.) Well, ?the syncing was easier...Strange things I noticed. ?

The idle speed was 500 +/- LOWER (with no adjustments yet made) on the warmed engine with the YICS box disconnected and the lines plugged. (The YICS box tests FINE for internal and external leaks)

Mixture needle adjustments made a HUGE difference in idle quality and even syncing when altered with the YICS box disconnected, but made little difference when I did it before (adjustments) with the YICS box still hooked up.

Re-attaching the YICS box AFTER syncing and mixture adjustments resulted in a 500 rpm (+/-) INCREASE in idle speed. (1300 with it OFF was just shy of 1900 with it back on with no other changes made)

Bottom line, rode into work (and right after the adjustments) and the bike has never seemed happier. ?It will even start easily on a warm day with no choke...So what do the gurus think?

[h2olawyer]

Hi Wolfman -

I won't claim guru status but I've noticed the same idle speed behavior with & without the YICS - after I fixed it.  As long as your idle is stable, it sounds like you got things right.  The YICS seems to help the bike run a little better and gives it a little more power but it also tends to mask some of the idle & synch settings.  It tends to make up for minor misadjustments.

Glad it's running so smooth now!  8)

H2O

[admin]

that brings up an interesting point and also something that I remember from having my 750 serviced at the dealer.
on the Seca, in order to sync the carbs, and adjust the mixture,
there is a special tool to disable the yics system in order to set the bike up. the tool blocks off the yics ports so you can get accurate adjustments.

in keeping with that same line of reasoning, it would seem that you should disconnect and plug the yics box while you set up the carbs , reconnect it when you are done and then set the idle to the proper speed.  I'm going to try this next time I sync my carbs and maybe try and document it.

I think this is a valid observation and although not in any of the manuals, may be the smartest way to setup the vision and probably should be standard operating procedure.

any thoughts ?

-Ron

[Lucky]

I'm pretty sure i've mentioned it a lot, but here it is again:
when I synq my carbs (did it yesterday in fact) I take 2 hemostats and clamp off the YICS hoses.
--Lucky

[harry_angel69]

If only we had a good manual.  Right?  ;)

[Lucky]

Ok, Ok, I promise to work on it more when it gets too cold up here to ride...

[harry_angel69]

I actually thought you were going to put up more of a fight to get me to shutup.  That was pretty easy.

I would really like to read what you already have done, so I have an idea what not to spend too much time researching.

drop me an e-mail.

[Glyn Pickering]

Been reading alot about synching the carbs, mixtures etc.
I have an 84 Vision and cannot find anywhere on the carbs a place I can turn a mixture screw in or out? I'm working with the Haynes manual ISBN 1 85010 761 0.  It says on page 99 the air/fuel mixture is not adjustable? Is this correct - and therefore no adjustment on the mixture screws needed?

Regards

Glyn

[RickJAB]

 ??? :-/ ??? ???I synced my carb also this weekend using the ATF manometer and plugging the YICS.
I had trouble keeping the ATF levels the same as everytime I tightened the rod it seemed to move some on me, but I got it better than when I started.  The bike ran much stonger with less hesitation.  I still need to rebuild the carbs, but I'll wait till winter.  
I also was going to try and adjust my air mixture screws but read the same thing as Glyn that they are plugged and not adjustable per Haynes manual.  After seeing Wolfman's results I'd like to give it a try.  Never have messed with adjusting a carb before so any help is appreciated.  Where exactly are they on the carberator and what do I have to remove before I can access them?  ??? ??? :-/ :)

[Sable]

     The plugs that you are looking for are on the very bottom of the carb near where they mount to the intake manifolds... It has been posted that they should be 4.5 for the front and 2.5 for the rear (or vice versa) to use as a starting point to tune the carbs.
     The problem has been that until now, just about everyone on the board has had carbs that have already had the plugs removed and the settings messed with, and no one knows what the factory setting was.
     Glyn and RickJAB... if you manage to get the plugs out, please make a special note as to what the adjustment screws are set at so we all can get a final answer as to what the factory settings were. I think this would be a great help to the rest of us when we re-install them after they have been rebuilt ;D

     ~Sable

[admin]

ok,
 Lucky can probably answer this better for 82 carbs as I've never worked on them.  there are plugs covering the mixture screws on these bikes per an epa mandate, they've been made tamperproof.
There are a number of ways to do it, I'll outline a couple of them.

What I've done on my bike is to drill a small hole partially into the plug and using a sheet metal screw, thread the screw into the plug, you can then either use a pair of vise grips and a hammer or dentpullr to pop these out.  On other vehicles where the plugs were stainless steel, ( designed not to be drilled out ) I've drilled a very small hole next to them in the casting and used a hook tool or small screwdriver to pry them out.
not sure on the 82's but they may be able to be removed with the carbs still on the bike.

Once you get the plugs out, I would immediately count the number of turns in and write it down somewhere, that will be a good place to start as a reference if you ever rebuild your carbs.

-Ron

[Lucky]

the dark circile at the very bottom right in the pic below is the pilot adjustment on the 82 carbs. the plug is aluminum and easy to drill. ?Drill a very small hole & thread a screw into it & pull them out with pliers. ?When you count the turns in, count them in to lightly seated. if you tighten them down you'll ruin them.
View this page to see how 83 pilots are set up: http://www.xz550.com/83mix.html
--Lucky

[RickJAB]

Sable/Admin thanks for the info.  
I hate to sound stupid but you are talking about the Main Jet?
Part of my problem is I hear the terms pilot jets/screws, main jets, air/fuel mixture screws etc....
    I am at work now but but when I get home I'll check to see if plugs are still there.   If so I'll be sure and count the number of turns in once removing the plugs.   I just want to be sure I'm adjusting the correct part.
    If I look at the Hyanes Manual on page 100 figure 4.1 it is shown as the Main Jet Plg, gasket, and main Jet?  Also shown on pg. 102 photo 11.11b item #2 Main Jet plug and main jet, and on page 104 photo 12.2 Main Scew Jet?

RickJAB

[Lucky]

those illistrations are all correct, & their all pointing to the same part.
BTW, if you look at Figure 11.11b, you can see the pilot screw plug. it's touching the bottom of the line that connects the arrow to the "1". remove this plug.
--Lucky

[RickJAB]

I found the pilot adjustments.  Unfortunately they had already had the plugs removed.  I tried them in a 1/8 and then a 1/4 turn more with worse results and then out a  1/4 turn more from my original settings with minimal improvement.  I'll mess with it more when I get time in the next few days based upon the starting points listed in various strings here.   Thanks for everyone's help in getting started.