UPDATE-yics substitute

[YellowJacket!]

There are other alternatives besides PVC such as Iron or copper.  I felt the iron would be too bulky, but looking at copper, it looks like it would work and pretty inexpensively and could be painted with high temp paint.
Anyone want to try it?

David

[VisionaryDan]

I just bought a bike that has a severely damaged YICS. Let me plug it up get the bike running and I'll try making a YISC out of copper tubing. Sweating an end and a hose fitting on shouldn't take more than 10 minutes.

How many oz or cc must the YICS hold?

Dan

[YellowJacket!]

one of the other threads that I read mentioned 70cc

David

[ProfessorRex]

I measured it, it's roughly 70cc (within 1cc) that's 2.3oz, 70 cubic centimeters... etc... I can give it to you in whatever unit you need, and if you give me the diameter of the tube you plan on using I can give you the proper length. (Although anyone who took geometry should be able to do it)

-Rex

[VisionaryDan]

Thanks, I'll let you know how I make out.  It maybe a week or so till I can get time to  get this new project running. But I will definitely give it a go. A couple pieces of copper tubing are a lot easier to find than a good YICS box.

Dan

[dchakrab]

Ok, enter the dumb newbie: What's a YICS?

I've been trying to figure it out from reading this and other threads...everything seems to go wrong on my bike, so after I get the petcock and carbs fixed, I'm assuming the next two words I'm going to have to learn are "stator" and "yics" ...what's the Yics do? Something involving air compression for the engine...but that doesn't make sense, since the bike isn't turbocharged, so...? On the other hand, if it's a simple air filter housing, it wouldn't be such a problem, either.

Someone enlighten me, please...

  -Dave.

[YellowJacket!]

Hi Dave,

The YICS is a small triangular shaped box attached tot he left side of the Visions engine and has two vacuum hoses coming out of it that attach to each cylinder.  The purpose of the YICS is to store up a little pressure and reinject it into the intake during compression...or something like that.  Its purpose is to help the engine obtain a little more horsepower and run a little more efficiently.  For the most part it is a pain since it can leak and on some "second hand" bikes had been removed or disabled by having some 1/4 " steel balls styck in the hoses.  If your bike idles irregulatly, it may be to a leaky YICS or one that is missing all together.  Check out Lucky's site www.xz550.com fo rmore info.

David

[h2olawyer]

From the service manual:

"YICS
To increase fuel economy through more efficent combustion, the engine is equiped with the patented Yamaha Induction Control System (YICS). In this configuration, the YICS consists of a chamber linked to the intake manifold by a tube.? Upon intake, the vacuume in the manifold creates a vacuume in the chamber; when the intake valve closes, the chamber draws in some air fuel mixture.? When the intake valve reopens, the mixture in the chamber shoots back out through an angled tube and into the cylinder, mixing with and swirling the main intake charge.? The swirling charge is then compressed and ignited, burning more completely and producing more power than that of a conventional engine"

So there is the "published" reason...

--Lucky

The YICS is the triangular shaped box that is (should be) located on the right side of the motorcycle, below the fuel tank & between the cylinders.? It has a chrome plastic cover.? The box itself (behind the cover) is made from two molded pieces of plastic.? The seam separates - either someplace around the outside edge, or in the center separator between the two internal chambers - or both.? There are fixes for it.? I think they all develop at least one of the leaks at some point in their life.? Mine was leaking with under 5,000 miles.

While you are getting your V running right, it isn't a bad idea to disconnect the YICS and plug each hose.? After you've got everything else sorted out, test your YICS & repair if necessary.? The testing procedures are found at www.xz550.com.? The repair method explained there has been improved - unless Lucky has updated that part of the site.? It is the method I used & mine's still sealed after about 3,000 miles.

Visions sure make for a good mechanical education, don't they?

H2O

[VisionaryDan]

What's with the ball bearings in the lines of the YICS. I just check out my original Vision and darn if it didn't have ball bearings in the lines. Since I have had the bike from new I know that the dealer must have done this when I had the 83 air box modification put on (back in 84). Did Yamaha recommend that dealers disable the YICS on 82 bikes? If so why would they do that after plastering YICS emblems all over the engine?

So anyway, I took out the ball bearings last night and took it for a test ride. The bike definitely runs different. Accelerates much smoother but I definitely need to do some carb adjusting and YICS module testing. Idle did vary at first from 1200 - 3000 rpm but it seemed to settle in about 2K.  So I adjusted the idle back down to 1300. There wasn't any problems with hard starting.

Maybe I'll make up those copper tubing YICS this weekend to try on this bike instead of waiting to get the second bike going.

Dan

[Lucky]

I've seen TSB's on the bike, & nowhere does it say to block off the YICS hoses. it had to be done to hide the fact that the box was leaking, probably after thay became unavailable.  pretty dam sneaky...! If they had just capped the ports then they would have had to explane WHY they did that  :o

I'm a little amazed that all these techs just happened to have 1/4" bearings rolling around in the bottom of their tool boxes...

[MotorPlow]

I'm a little amazed that all these techs just happened to have 1/4" bearings rolling around in the bottom of their tool boxes...

Maybe they worked on a lot of Visions with leaky YICS Boxes  :-\

[Junior]

Could use some opinions from YICS pros. Found Liguid tape at WalMart today (Service range -30*F to +255*F) In the sporting goods section, found a aluminum bottle charged for inflating flotation devices among the life jacket counter supplies. Neck appears to be 1/4" . Larger than normal co cartridges. $9 to $10 range each. Appreciate if some of you on the forum would look at this next trip to WalMart, and post your opinion regards YICS subsitute. Just looking at it through package, it looked perfect for V. Thanks J

[ProfessorRex]

Junior,
What's the volume?

[Junior]

Thats the kicker-I don't know and could not tell. It is in  a vacum sealed plastic container,  and no one in sports department to get permission to open it.

[ProfessorRex]

If it's near 70cc/2.3oz it's good to go

[YellowJacket!]

I finished my copper pipe YICS yesterday.  I used 6" of 3/4" copper pipe with two endcaps (the cashier at Lowes was quite inquizitive) for each chamber.  I also got two 1/4 inch brass nipples for the hose connector.  I bored out two of the endcaps and inserted the nipple adapters then sweated an endcap and endcap with nipple adapter to each 6" pipe.  The arrangement is a bit larger than the original YICS but I soldered them in a "V" to a bracket and will mount it in the original place whan I get my bike back together. 
I'm back on 12 hr shifts fo rthe rest of the week, so the bike gets a rest but I hope to take some pics of my work this weekend and post  them here with pics of my YICS.  Total cost was under 20.00

David

[VisionaryDan]

Rex

Are you sure about the volume for each cylinder is 70cc for the YICS?

I was wrong about my orginal dimensions. Here are the correct sizes:
I calculated it using 1" dia. copper tubing (1.035 ID) to get 70cc would need to be approximately 5" long. That seems a bit large comparing it to one half of the YICS triangular chamber.

I plan to make these up this weekend.
Thanks,
Dan

[ProfessorRex]

Yes, I measured twice by volume, and once geometrically by dimension.  The shape of the YICS hides its depth.  If you'd like to check it yourself, it's quite easy: 
Split it open, and see how many teaspoons of water fit into one half of one side of the yics, then do the other half of the same side, (measure one chamber) I got 14 teaspoons, that's about 70cc's, 2.3 oz, 4.2 cubic inches.... etc

Before I did it by volume with water, I carefully measured it and did the volume geometrically.  I came up with almost the same number each time, within a few cc's.

Being hyper acurate is probably not that important because the volume of the hoses is different.

I posted 70cc's because it'd be easier to find a co2 or other type container in that volume.
2.3oz's seems to be standard size for small hotsauce containers.

If my fixed YICS doesn't hold (unlikely as I repaired it with JBweld) then I'll use two 2.3oz tabasco bottles.

-Rex

[Blake]

thought i'd chime in with some quick ideas. (some might have been said, some might not

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jhtml;jsessionid=BIKRZLTU4K5HRTQSNOHCCNOOCJVZCIWE?id=0025950226302a&navCount=0&cmCat=srchdx&cm_ven=srchdx&cm_ite=srchdx&_requestid=33847
4oz co2 containers- 10 bucks for 2.  (dont know fit they mean weight or volume?  56 grams.

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jhtml;jsessionid=BIKRZLTU4K5HRTQSNOHCCNOOCJVZCIWE?id=0025950226302a&navCount=0&cmCat=srchdx&cm_ven=srchdx&cm_ite=srchdx&_requestid=33847
16gram co2 containers (threaded noses..).  again not sure of volume, it says it weighs 16 grams

im looking at these 4oz co2 cylinders
http://shop.store.yahoo.com/actionvillage/030-0025.html
theres another one..  now it says the small co2 cylinders at 12grams. 

if anyone can find the dimensions of those, they might be a quite high quality/good looking substitute (i know i'd get them).   I bought two 20oz aluminum co2 containers to use for nitrous bottles on a bike (co2 and nitrous have same pressures so tanks are interchangable).  I think they cost me all of 15 dollars a piece at walmart, whereas if i bought them from a real "nitrous" place they would be 50+ each.

I'll have to go see if there are any of those 4oz cylinders around here this weekend.  I'll buy a set and see how much volume they have.



Blake

[VisionaryDan]

Hey,

I built the YICS copper tubing replacements. I was able to install them under the tank wire tied to the frame. I used 1" copper tubing T fitting with a 1/2 pipe from the center. With the 1" end caps this came out to a perfect length 5" to give me a 70cc chamber.? I then soldered a 1/8 pipe threaded adapter into the 1/2 inlet and screwed in a 5/16 hose end.

I pressure tested both chambers and everything was sealed tight.

At this point I believe I need some carb adjustments due to the fact that my YICS had been disabled for 20 year and its been a long time since the carbs were sinked. The bike now has a bad case of the stumbles and is running hot, which makes me believe that its running lean.? Or maybe my math is wrong and 1" ID pipe 5" long doesn't equal 70cc.

Ironically, I'm running an oversized jet in the front carb due to the Keaster rebuild kit using the same size jet for front and back. You would think would make it run rich?

So, if the carbs are out of sync will that cause the engine to run lean? If not where should I start? to look to resolve this problem?

Thanks,
Dan