YICS tool - unnecessary?

Tried to get my yamaha dealer to order a YICS tool for me. They resisted, saying that I didn't need one to synch, just the vacuum dials. They know my bike, a 1982 xj650j with a YICS engine. What the hell are they talking about?

 

Oops, sorry for the language. I meant, what the heck are they talking about?

 

I sync'd my 82 Seca without a YICS tool and the difference was amazing, I would say that at low revs, the small size of the passages would be too restrictive to have a major effect on the vacuum readings. I may be wrong, but I didn't use a tool and it runs great.

 

This has been debated many times before; do a search in the forums.

Short answer: as I understand it, not blocking off the passage throws off the readings. After all, they designed and built the tool for a reason, no?

 

Yes it IS important.

But the real question is:
"Why are you BUYING a yics tool"

There are many methods to make an inexpensive tool to accomplish the blanking tecnique!

What the tool allows you to do is adjust EACH carb.
They are all linked together by this passage. Thus equalizing the vaccum.

You CAN be in the ball park w/o the tool, but you can pick your seat w/ the tool!!
Its more exacting.

Debate is still ongoing, and I do enjoy the theories!

 

I think the YICS Passage should be blocked-off when you are doing Sync.
The YICS Ports are on the Intake Manifold side of the Carbs and will compensate for a High or a Low Vacuum while the Sync Gauges are taking Vacuum readings.

I have changed my mind about needing the YICS Tool for Pilot Mixtures Adjustments.
My experience on adjusting the Pilot Mixtures is that you will get a better Idle and just-off-Idle Mixture if you set the Pilot Mixtures without the YICS Tool and tune the Bike as it would be running without the Tool inserted.

Last Summer, I experimented with Pilot Mixtures and successfully tuned my Pilot Mixtures to Ultra-Fine-Tuning ... by making small adjustments to the Pilot Mixture Screws without the YICS Tool.

Plug Reads told the story!
My Mixtures for Idle and Off-Idle were exceptionally good after tuning the Bike for Pilot Mixtures without the YICS Tool.

Sync ... Yes, Sync with the tool.
Mixtures ... Ideally, use the tool ... but, if you don't ... you'll still get Pilot Mixtures that are right on-the-money!

 

I STRONGLY second Rick's opinion and results.

While the YICS passages may be small, they can still move a great amount of air/vacuum at low engine speeds (or any engine speeds) and thus "contaminate" the vacuum reading of other cylinders.

A small hole in a balloon is just as large a problem as a big hole.........

 

lets face it yics was a marketing gimmick, that really doesn't really do much

 

The YICS Racing Engines were dominant in the Era that Yamaha Raced them against all theh big motorcycle makers.

I think it works when you are in a highly synchronized condition.
If you're not tuned up ... it doesn't matter.

 

yamaha-japan

maybe they won races because they didn't have to stop for gas

 

Well, now I'm really confused. (>

Cheers,

Phil

 

Hi,
I'm a proud (UK) owner of an XJ 750 Maxim US import and would welcome some advice. Some of the forum have made a YICS blanking tool. Can someone send me the dimesions and we'll make the tool ourselves as Yamaha UK are'nt selling the item.

Its a great bike shame it never took off in the UK I am one of very few owners here over the pond. Thanks

 

vLibero61, I do offer reproductions of the original YICS port blanking tool:

v7) Reproduction YICS Port Blanking "Block-Off" Tool---this is the tool you'll need to perform a proper carb synchronization on any YICS motor......without it, you're just wasting time. This block-off tool is used to isolate each cylinder from the others while perfoming a carb synch. Updated version of the factory #90890-04068-00 tool. Some people claim that this tool is NOT needed to perform a proper synch; we disagree, and so do the Yamaha engineers who designed the YICS system. Quality aluminum tool features a snap-open and shut trunnion handle design like the original. This is NOT a cheap home-made tool and has all the proper seals, dimensions, and high-temp insulators as an original factory tool. IN STOCK! This tool works on ALL YICS engines, regardless of engine size!

HCP93 reproduction YICS port blanking tool, each:
$ 37.00


Any questions please write again! I have lots of items listed for sale (and even more items that aren't listed yet!) which you can review over at the xjbikes.com website:

www.xjbikes.com/Forums...t=135.html

 

Gimmick, well...
I'm with you that it didn't do much for power buuut it does improve combustion efficiency, which theoretically is more power. But to my thinking (and the seat of my pants) the 2 hp gain isn't all that noticable.
I have noted a marked idle improvement by using the YICS tool.
As easy as it is to make and the improvements it makes on the tune of the bike make it a no-brainer in my book.

 

My New Age Thinking on the YICS Debate will only confound the situation.

I do the Carb Synchronizing using the YICS Tool. That way you get what each Carb is pulling without being affected by the neighborhood ... which is substantial at lower rpm's.

Once I get the Carbs Synced ... Out comes the Tool and the fine-tuning begins.
I have crossed-over to the Dark Side that doesn't use the Tool for Colortuning or setting the Pilot Mixtures.
The rationale is: Tune it like its going to run when you are riding it!

Until someone comes-up with a handy-dandy "Insert" that you can press-fit into the YICS Chamber and block it off ... you might as well Tune it for the way its going to act without being blocked-off.

There is such a slight variation anyway, but the Pilot Mixtures seen to be easier to Dial-in without the tool.

I'm at the stage where I'm making mi-nute (sic) adjustments to individual Cylinders; anyway.
I've Colortuned to the Rich side of the blue and then moved the Screws IN a degree or two at a time to get the desired results.

At the moment, I'm pretty sure that the Bike is about as finely-tuned as the Engineering will permit.
I have each Hole doing a leaving a nice light brown stain on the Spark Plug's Center Electrode's Ceramic.

If I add a degree or two of Richness to the Mixture ... it becomes a very smooth and comfortable, cool-burning all-day cruising Mixture, with Engine "Coasting" upon closing the Throttles.

Where it is,, right now, is a Performance Tune ... Lean -- But, not "Critically" Lean to be a quick and highly responsive to open Throttles and have moderate Engine Braking when the Throttles are closed.

As I have eluded too in many other Posts ... the "Window" of adjustment to the Pilot Mixture Screws to achieve these tuning parameters is very narrow.

The width of a Nickel or a Dime in adding Richness or Lean-ness to the Air~Fuel Ratio.

You have to be willing to buy a 4-Pack of Champion NR9YC Plugs to replace the ones you READ for making your Mixture adjustments. It's best to be able to monitor the Mixture's effect on NEW Plugs.

That way there is NO confusion about whether or not they have changes since the last READ.

You KNOW ... for sure!

 

I know that the factory didn't have a colortune plug available, they used an exhaust gas analyzer device.......what was their recommendation on the use of a YICS tool while doing pilot mixture adjustments?

 

When the Bikes were new, the Factory supplied the Dealerships with Exhaust Gas Analyzers. (EGA) Initially, the Bikes were set-up for EGA with the Tool in place.

Once the EGA Machines started breaking down and the Dealership was required to pay for their repairs and calibrations; the EGA Machine was unplugged, its leads wrapped around the Machine and pushed over into a corner where they collected dust. The Tech's resorted to tuning-up YICS Bikes "By Ear".

Idles and off-idles wer the main concern. Keeping the Bikes on-the-road was paramount.
There became a "Standard Operating Procedure" for setting the Pilot Mixtures on Bikes which came-in for service with the Factory Anti-tamper Plugs still in place.

Remove the Plugs and add just a little less than a quarter-turn to Factory Settings,
This ballpark adjustment generally kept both the owner and the dealer happy because the bike would run pretty good and everybody was happy.

Today you would be hard pressed to find a working EGA in any Yamaha Dealership.
Our Bikes are considered a nusance to the Dealer and a growing number of Dealerships are coming-up with some excuse to turn you away when you show-up looking for any tune-up related servicing.

They will be delighted to sell you a battery, a tire or attempt to order you some parts for the bike; but once you say you want Carbs Cleaned or a Major Tune-Up done, the excuses start to fly.

Everything from flat-out saying they don't work on those bikes any more to we are booked-up in Service; you'll have to try to see if you can get your Bike in somewhere else.

Those that DO work on the old XJ-Bikes make you pay an hourly rate.
They do what they have to do to get the bike "Out-the-door"!

So, instead of paying through the nose, we have been forced to learn how to service our bikes ... ourselves!

Now, we have the Colortune Plug and devices for Synchronizing Carbs that don't require Mercury. (I have Mercury Sticks ... I need Mercury)

We have the ability (in most cases) to tune these bikes as we please.
Arizona's emission requirement might be strong enough to reject the vast majority of self-tuned bikes. I'd venture to say that the vast majority of Forum Members Bikes are too RICH for the Arizona requirement.

So, the majority of us ... not under sanction of an Emission Requirement, tune on the RICH Side and enjoy riding a bike that wont stall-out despite having it tuned in a manner that would not satisfy the Environmental Protection Agency's Standard for when they were new!