Mixture screw & YICS blocking tool

I've been reading many post on the fuel air mixture screw adjustment on my 1982 XJ 750 and have not seen any one ask or address this. For best adjustment of the carbs to each cylinder is it best to have the tool installed or not? If so why or why not?
Thanks
Joe

 

It is said to be best to use the tool, coz then you are adjusting individual carbs like when doing the synch' you are adjusting individual carbs, with the tool installed. Oh damn the can of worms got knocked over (debate likely to ensue)

 

Hey ! Welcome Zoutlaw !!
The answer to your question, according to my Magic "8" ball is- - No !
Unless you are using a ColorTune or Exhaust gas analyzer,
you do not use a YICS tool for any of the other techniques for adjusting the Pilot screws.

 

Negative, leave the yics chamber alone when adjusting and reading plugs.
It has gotten me better results in the past

 

I neglected to mention colourtune, sorry.

 

One more question for everybody. When is the mixture gets richer when you turn in the screw or when you turn it out?

 

richer out l

eaner in

 

Scholz- Thanks for the answer but some think the opposite. Could you explain why?

 

I would guess it's a misconception about what the mixture screws control, air or fuel (they control fuel.)

 

how many turns out should they be, as i was going to buy the tool, as me carbs are all over the place, my gsxr bike is 2 and a half out, i put k n ns on it, turned them out anuther turn, runs fine, i was told not to touch the carbs screws, as itll make the bike run bad, she is any way?????

 

Technically ... The Mixture Screw Controls ... AIR.

BUT, the AIR Passage is drilled so that it intersects with the Pilot FUEL Supply.

As more AIR is allowed to "VENT" to the Vacuum of the Intake Stroke ... the AIR draws-up with it ... FUEL from where the Pilot FUEL Jet is drilled into the AIR Passage.

This is why the Pilot Mixture Screw has such a SHORT Window of Mixture Regulating.
Depending on the Volume of FUEL Jetted into the Passage the Mixture can be regulated until the Metering of the Fuel by the Jet regulates flow.

 

ta mate,ill try the air screws in, first,then if no good out, as it needs to get sorted,

 

Speaking of ColorTune plug... Where can I get me one? was going to make me a Yics tool, but think I can get by without unless you guys think otherwise.

 

Do a forum search on YICS and read the whole debate.

There are very valid opinions both ways, the simple fact is that using the tool is what Yamaha recommends and it DOES make the process easier.

You can accomplish the same state of tune without it, but it requires more luck and apparent skill than I personally have so I use it. I've tried sync'ing (and colortuning) both with and without, and came to the above conclusion by virtue of the experience(s.) Others have had different experience.

You can order a ColorTune directly from the manufacturer, Morgan in England, but I believe chacal (see forums, supporting vendor, XJ4Ever) carries them also.

 

TO me it does not makes sense to NOT have the tool in when doing the air/fuel mix screws. The manuals say to stay away from them. But I understand the emissions they were trying to achieve by having the bike lean was beyond Yamaha's control due to regulations at the build date of the bike. Thanks for the answer. (Scratching my head now and trying to help catch worms)

Joe

 

OK, worms it is. The mixture screws were originally set using an EGA, which was problematic even for Yamaha dealers. We have the visual equivalent, the ColorTune, to assist in setting the mixtures rich enough to make the burn "happy." We probably do end up richer than the factory, but the motor is more reliable as a result.

Trying to achieve ANY precise adjustment without isolating the cylinders is an exercise in frustration; that's what the YICS tool is for. Like I said, do a search on YICS and read the furor.

I like my 550 that idles like a sewing machine. OK, both of 'em. (worms ahoy...)

 

I had achieved better results cheking the plugs for color than the colortune!

 

Agreed. FINAL mixture adjustment comes from real-world application.

ColorTune gets you in the ballpark. I didn't believe in it until I bought one and used it. You do still need to do the final tweaks based on the plugs.

 

I set the Sync and Idle with the YICS Tool in place.

Then, I pull the Tool and treat the Mixture to each Carb individually.

My working theory on the process:

"Tune it the way you are going to ride it!"

 

FWIW I agree with Fitz and Rick, and the final tweak is very small.

 

Thanks all for the input. Question answered

Joe