Y.I.C.S tool horror.

I just synched the carbs on my bike (81 xj550, mikuni carbs) using a yics tool that is (or was) an aluminium rod with a series of o rings along its length. You know the type.Afterwards the engine sounded perfect, but to my utter horror, when the tool was removed several of the o rings had gone. So bits of them are stuck somewhere in the yics passageway, and worse, I cant see them anywhere. :?: Also, on twisting the throttle - the engine would race , needing me to cut the ignition.. I suspect the two are linked. This happened to anyone else? Any ideas about getting the bits out? I dont have access to compressed air. I have a couple, the very LAST of which is a stripdown. This is like one of those nightmares you wake up in a cold sweat from. Any help massively appreciated. Cheers.

 

The 2 are not linked, trash in the YICS system won't cause a hanging idle.
Loose boot clamps, bad throttle shaft seals (8 of them), cracked intake boots and caps, even the boot-to-head seal can let excess air in.

Get a rifle brush, or coathanger and cotton Tee shirt strips, and carb cleaner, and start scrubbing. Hopefully you didn't suck a fragment into the tiny runners - you could save the "trash" and see if you got it all.

Then throw away that inferior tool.
You can pack the YICS passage with oily Tee shirt strips the next time.

 

You are supposed to spray the YICS tool with silicone lube.

Do not run the engine for very long with the YICS tool in place. If it takes more than a couple minutes to synch you are doing something wrong.

The dual-bottle differental synch is very fast for balancing pairs of carbs.

 

oily Tee shirt strips the next time????

How is it done?

Thanks!

 

I sprayed the tool first alright. And on thinking it through rationally, instead of in a state of shock, you're right - they cant be linked. I got an airleak somewhere. It's fishing out the bits of o ring that's bothering me. And whoever said "throw away the inferior tool" , they got that right too. DO NOT USE one of these "yics eliminator" tools. Somebody loaned me the one I used. The o rings are vitton, or vitron or something. With any luck they might just get pulled through and out the exhaust without causing harm. Does anyone know of a full exploded diagram of the xj engine ? As i find these far easier to work with. Thanks for the help. I am off to get very drunk indeed.

 

How long did you run your bike with the tool in place?

 

Yeah...

I have an unused (so far) eliminator tool and this is the first BAD thing I've heard about it. (I got the professional looking one off eBay before I read about the oil stuffed T-Shirt).

 

Using the factory style YICS port blanking tool for engine synch purposes is highly recommended.......for a reason.

The YICS ports on the 550's are pretty large, you could conceivably such up a wayward piece of an o-ring (a small piece) into one of them. The passages on the 650 - 1100 engines are tiny, so you can't such up anything into them, but you can melt an o-ring into them and thus "weld it shut" with rubber material.

You need a helper, a strong flashlight, and a right-angle wire probe tool to "feel" up into the YICS ports, and determine if there is any restriction, and if so, ream it out or loosen it up. A small piece of material could conceivably be be sucked into the passage, but it would also be taken into the combustion chamber and be elminiated.

 

If the O-rings are Viton you can stop worrying about them being melted. Even plain Buna rubber should not be a problem at all.

 

Just to make sure to eliminate the obvious: melted YICS tool and racing idle could be related...if you forgot in all your horror to reinstall the YICS plugs.

 

:?: I ran the engine with the yics tool inserted for maybe three minutes- like the other bloke said, synching the carbs is a quick and easy task. It was removing it that I believe Either cut or had enough abrasive effect to split the o rings. Now....imagine that the circular passage behind the yics plug is a clock face. At what o clock are the actual passageways facing/angled? I intend to use some kind of probe, together with a rotary action and do not want to shove any bloody bits further in. I also spent a sleepless night considering everything- and the possibility of leaving off the plugs came up, but no, they're on alright. I have heard of people blocking off the yics system, even saying it improves performance. Could this be a last resort? At least I'd know the carbs were pulling equally. Again, thanks for your help. I am a ex motocross rider- if the number of cylinders/carbs etc go any higher than one, I get all confused. Cheers again.

 

I'll knock up an L.E.D. on the end of a knitting needle or something , and a length of stiff wire with a right angle bend at the end to do the digging. What happens if I cant find it all? What is the WORST possible outcome? I tried to explain it to my wife by saying " imagine dropping a crystal glass that shatters into a million pieces , and you HAVE to find every single last bit, because they are all deadly poisonous" That was when she saw my face and asked how serious it was. ( i once had to explain to her the difference between a wheel and a tyre to her- trying to explain the above would have been impossible.)

 

I personally don't think it's THAT serious. You didn't pour sand into the engine, rubber at worst will clog up a passage so a cylinder doesn't get the "spin," and at best, will melt and burn and be blown out the exhaust. Just pass a brush (something softer than aluminum) from one end to the other, maybe wrap it in the shop rag to wipe up the result.

The YICS port is just a hole drilled from end to end, and the ports into the engine are drilled at *12 o-clock*. The outside ones are only like an inch or two from the edge of the bolts, and can be cleaned with a dental pick. Think of it this way, if running the engine at speed melts the oring further, it'll run down to the bottom of the passage and collect if it doesn't get sucked up, ready to be cleaned after a couple of miles.

I don't think there's even an intake to that passage, it's just shared between cylinders so that when one is drawing air through the end of the intake stroke, one is blowing air in at the end of the power stroke, and the other two are closed off.

The YICS has a small effect, but your engine won't be ruined under just about any circumstances. You could do ALOT worse :twisted:

 

Sound advice. The only thing I would do different would be to apply vacuum from my shop vac to one end of the YICS passage while poking, prodding or brushing. And once done poking, prodding and brushing I would keep said vacuum applied and roll the motor over slowly a couple revolutions (to open all the intake valves in turn and allow backward airflow through the YICS ports.)

 

If you have an air compressor and fittings from a compression tester, you can pressure-up each cylinder, and with the intake valve open and the carb butterfly closed, the high pressure air would blow out the YICS transfer passages, dislodging any blockage.

You would want to "lower" your idle, and you'd need to roll the engine over to "intake bottom dead center" and use as much pressure as possible.

You'd still want to collect all the bits that came out to know that you got everything.

 

Just a question...is there any danger of sucking fuel through the YICS passage that could ignite while passing through a shop vac? Should the carbs be taken off just to be safe?

 

if you have a compressor and take the carbs off put a cylinder at TDC
fashion something to let you blow air in the intake
shoot some carb cleaner in the intake then some air

 

Or, do like TIME said, use a compression tester fitting to blow air into the cylinder, do it with the intake valve open and it will blow back thru the YICS passage too.

Might work even better than trying to "suck" it back out.

 

Won't you blow crap back into the carbs, Fitz?

 

I thought of that one too. Only thing is- i only got a foot pump. I have found a surprising ammount of bits of o ring. Just got to piece them together. Thinking about it, I might just get a compressor. Thanks to all you people, I expect you have all experienced that feeling of despair at one time or another, and you have all managed to alleviate it to a large degree. I'll get it sorted one way or another and I'll let you know what worked. My poor wife; she said "it's just one thing after another" - to which I could only reply "it's an old bike, this is what happens (without adding - "they are vast money pits"). How many of you have NEVER had to use that one at some point? Yep, open the intake valves and blast the poxy stuff out. Again, i repeat- dont use the cheap yics tools - they are trouble. GET THE PROPER TOOL. Again, thanks to all of you. Best site on the web.

 

Blowing crap back into the carbs is the last of my worries!

 

whats going to happen in the carbs when they see pressure on the engine side ?
they might blow gas out the fuel line, they might blow gas out the emulsion tube or the diaphragm might blow up like a balloon, i don't know but go easy
why would any air go out the yics port when it could go out the carb?

 

If the 2 caps for the YICS are off, the pressure would blow from the cylinder, thru the open intake, then thru the small transfer ports, then into the YICS main port. Only incidental small bits of carbon would be blown back to the carbs, if any.

You might have to look at the cams to get the phasing correct, where the cylinder has the intake open.

 

Only small bits of.........push the thing home (

 

Make a Tool to Clean the YICS Port.
Hardwood Dowel, Fiberglass Driveway Marking Rod.
Small Bore Rifle Cleaning Kit.

Drive small Wads of Terrycloth soaked "Patches" in one side and out the other.
Keep Cleaning until the one that comes out after cleaning is as clean as the one you sent in.

You can fabricate another Tool to "Explore" the actual Ports.

You need a Solid length of CB Antenna.
Heat and bend a Right Angle at the end.
Dremel the Probe-end to be able to fit the YICS Port.

Scribe a Mark on the Antenna at each "Interval".
Finish the Probe End to be sufficiently smooth enough to not damage an O-ring.

(( Get a used YICS Engine Hex Plug Drill a small hole in it. The diameter of a Carb Cleaner Red Tube. You can shoot Carb Cleaner right into a running Engine. ))

 

whats yics??! :?: go ahead and laugh just answer the question first

 

Young Informed College Student, I think...

 

Good news anyway. The o rings were actually minced up into tiny little bits. A simple 4 hour search and I think I've got the lot. The engine racing was caused by (after fitting new inlet boots) the old spigot caps not sealing properly. So anyone replacing the inlet boots - I'd advise you to get new caps for them too. A carefully crafted tool (old clothes hanger] bent at one end allowed me to be satisfied that the yics ports are clear. Again, as someone previously said - use the proper tool and save yourself potential hassle. I'm sure plenty of people have used the 'yics eliminator' without any problem at all, but I'd be willing to bet that I'm not the first this has happened to. The edges of the yics ports are sharp aluminium. The o rings are soft rubber. The oily rag thing got me interested - has anyone tried it?

 

phil29 that is good news indeed; the oily rag will work but so does a proper replica of the factory tool.

That was why I originally suggested the vacuum idea. You certainly would if they were still on the bike.

But then further discussion seemed to indicate the carbs were back off, or soon coming back off.

Now it all appears to be a moot point, with the exception of possibly WHAT YICS block-off tool to use.

Like I said I strongly recommend the "factory-style" tool; I've had no problems with mine. (My home-made one melted in the passage--not fun.)

apsolus you reaallly need to use the "search" function. YICS=Yamaha Induction Control(?) System; or is that Yamaha Intake Complication System (it's actually very simple.) It's a series of interconnected ports behind each intake valve that receive a "boost" from the cylinders NOT on an intake stroke, to "swirl" the intake charge as it enters the combustion chamber. It supposedly makes the fuel burn more efficiently and cleaner while helping to produce more power by allowing more of a charge to get "packed" into the combustion chamber.

Does it work? Use the search feature and read the debates. Personally, I think it does but my two running XJs are YICS-motored bikes.

The "YICS tool" is used to block the system for accurate carb sync adjustments.

The "YICS Eliminator" is an unfortunate bit of mechanical tomfoolery that is hawked on the innanet; and unfortunately some folks get sold on the idea. Yamaha designed a proper tool for the purpose; IMHO the best tool to use is the replica of the factory one.

But then again, I'm one of those who think Yamaha really did know what they were doing, and don't try to out-engineer them; rather just take advantage of and apply advances in technology they couldn't have known about (like proper fuse box clips.)

 

im not in college! haha ok got it i was thinking yamaha intake combustion system or someting im close. good deal. sory about not using the search function i deserve my sculding :cry:

 

I claim to be the "Inventor" of the "Stuff Method". (Oily Rag)

Needing to Sync a Bike and forgetting my Tool, ... I Stuffed the YICS Passage with a, ... long, thin, ribbon of Tee-shirt soaked with Marvel Mystery Oil.

The experiment was successful and the results made known to the Community needing a substitute Tool as an alternative.
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The YICS System is but one component that contributes to a well performing Engine.
Blocking-off the Passage won't make a rough-running bike run better.
Most likely, the so-called "Elimination" device will have and adverse effect.
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Having the Bike "Dialed-in" and Fine Tuned in it's Stock Configuration, requires a sufficient amount of work and tuning for which there is the reward of:

Having Tuned-up your Bike to a High Performing Level and NOT needing to do anything more than ride it and change the Oil for months at a time.
Get-on and go. Enjoy getting a sunburn.

Making alterations to the Carbs, Intake and Exhaust to "Improve Performance" [or appearance] makes it far more difficult to achieve a level of Fine Tuning, without a great deal of tedious experimental adjustments than you might expect.

 

Agree with you Rick. The 'rag system makes perfect sense but what type of oil do you us? The one you mention is a mystery to us in Britain. High melting point? Copper slip?! Tar? As a final comment, I turned over the engine until the inlets were open, and with the carbs (yet again) removed, blasted air down the spark plug holes. Tedious, boring, tiresome and most of all NOT NEEDED work to do... but it worked. As you say - DONT use the "eliminator". All it does is eliminate the ammount of time on the road.

 

The original post refers to a 1981 XJ. I thought YICS started in '82?

 

Marvel Mystery Oil is a brand of "Top Cylinder Lubrication"

It's UK Equal would most likely be, ... "Lucas Oil Upper Cylinder Lubricant and injector Cleaner"

http://www.anythingtruck.com/Merchant2/ ... e=LTA-PERF

 

Love my '81! No YICS to worry about! KISS

Rick, you should know better than to forget your tool!

Loren

 

YICS appeared for the 1981 Debut of the XJ550R and XJ750R Secas. The Maxim, which had come out in 1980 without YICS, didn't get YICS until the '82MY. The 550 Maxims all had YICS as well.

The original post referred to a 550.

 

Another good substitute for "Marvel" would be 2 stroke oil, as it would be just as harmless to the engine.

"Marvel Mystery Oil" has about the appearance and consistency of Automatic Transmission Fluid.

 

Ah. Learned something today! Thanks!

 

I"m the Mutt whose Yics eliminator was trashed in this thread,I have used it no problems at all, and have had to buy a second one to replace the original,and have had no problems.Original YICS tools were dealer tools and are not easily available and therefore expensive and the tool i have seems to be a superior option to the threaded rod variety.