what is yics ???????????

hi what is the yics exactly what is the advantage to have a bike with yics is it better to have it or not thank you im new to this stuff please let me know ivan

 

yamaha induction control system

 

YICS is a defensive pattern run by the Bird era Celtics.








Sorry, I'm drunk and it's my birthday.

 

Happy Birthday!



Jim

 

YICS....Yamaha Induction Control System....is basically a balance port which connects all four carbs to each other for a hypothetical fuel swirl effect of dubious value, hence the need to block it off (according to Yamaha) when isolating the carbs for synchronization....(read; "divide and conquer")
Long story short;
If you have a YICS bike, you should use the YICS block-off tool prior to carb sync.

 

I know I'll ruffle feathers, but I think the yics tool is total bs. I've had about six maxims from the early 80s and I never ever used a yics tool, just regular sticks. Never had any problems.

 

Consider my feathers ruffled. Now, by "sticks" what do you mean exactly?

The YICS balances vacuum between the 4 cylinders. By blocking those ports, using a YICS tool (or similar tool that seals the passageways between the cylinders), you can make sure all 4 carbs are working properly. By not blocking them properly and independently, you are then sharing a common vacuum and a improperly tuned carb may be compensating for another.

End result, you may have a working, functioning bike, but your gas mileage, plugs, oil, and seals are all going to pay the price for what you consider "BS".

I feel sorry for all 6 of your bikes.

 

Everyone has their opinion. You are most certainly entitled to yours, and I'm not even saying you're wrong. That being said, I feel I should air my opinion as well. Mine is this; Yamaha had no purpose for recommending the tool being used in their service manuals (beside the obvious draw to "scare" riders into bringing their bikes to an authorized dealer....no surprise there!) other than the plainly obvious......it works. Bear in mind three things; 1) The factory service manual was written for factory trained technicians working at factory authorized service centers with access to factory tools. 2) Even paying list price for the factory tool, the one-time purchase price is less than a tire change at most shops. So if profit is not the driving force behind recommending using the tool, what else could be? 3) Using the tool can't hurt. I'm sure you could sync the carbs without it and have the bike run decently. In fact, I'll bet I could sync the carbs by ear WITHOUT mercury sticks better than some of you could....but does that mean it's a good idea, or that I would shoot anyone down for using sticks just because I don't? Hell no.
To each his own. Not drawing fire on you, brother, just stating the maybe-not-so-obvious.

 

I should throw some weight into this discussion, but to be honest it's been done so many times before and always ended in tears, so I see no point rehashing my opinions and further putting noses out of joint.

Search is your friend.

 

Has anyone ever done it both ways? I have to sync my carbs this week or weekend, and Im gonna try it without the yics tool first, then stick the tool in there to see if it makes a difference. I will report back my results a.s.a.p.

 

I have seen a user on another thread say he had tried boith and that the results were better using the YICS tool.

I have snyc'd mine without and been pleased with the results as have others. I am having trouble finding Marvel Mystery Oil locally to try Rick's clothesline/MMO (thread: Free YICS Tool For All) tool to see if I can get it better.

If you sync without the YICS tool, set your idle higher. For mine I set it to 1400 up from 1050 RPM. This is because the higher idle lessons the effect of the YCIS system.

If you remember the Yamaha IT Enduro 2/strokes of the '80s, they had YICS. What it was simpily a hose from the intake between motor and carb (same place our YICS enters the intake tract) attached to a rectanguler plastic bottle. The idea being that the bottle would hold a small amount of air/fuel mix, when the throttle is snapped open the engine draws on this "extra", "instant" charge. This results in better throttle responce especilly at low revs.

Manufactures started making "boost bottles" for ya 2 stroke off roader. YICS by another name. Adapted one to me jetted by a pro 2 stroke 45 HP w/cooled single Suzuki TS250RH, did not notice any difference, but that thing was insane screaming hole digging power from idle to redline anyway! :twisted:

YICS is not designed to ballance anything anyway. 8O

Now our XJ CV carbs have good throttle responce that fixed slide carbs lack. The YICS on the XJ probably does not make much difference as NON YICS XJs still rock just as hard as YICS bikes! (Don't they non YICS owners :wink: )

 

As many bikes as I have tuned at carb clinics I have never not used the YICS tool. So I would be very interested in your findings. Carb clinics don't usually alot enough time to tune bikes twice. I have reservations concerning tuning without the YICS tool so therefore don't. But since we are only setting the idle mixture I don't think it would be too critical to running operations. Once past 3k RPM the idle jet has relinquished part of it's job over to the main jet anyway.
So please report back your findings, I will wait with anticipation!