Can carbs be sync'ed with using a YICS tool?

1985 XJ 700N, air cooled. I've been told that the carbs can be sync'ed without using a YICS tool, but it just take longer. Any comments?

 

It can be done without the tool, it doesn't take any longer. For the purists, it may not be QUITE as accurate, but for the rest of us it's darn well close enough.

FWIW, I have a too. It's brand new....and still in the plastic. It looks really really nice and I can show it to people at carb clinics.

I can usually have a bike synced in a matter of a few minutes. It really doesn't take that long unless the carbs are WaAAAAAAyyy out of wack. In that case, there's probably more carb work that needs to be done first.

Ok, everyone else can fire away now.......

Dave Fox

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i couldn't have said it better myself

 

Thanks. I'm not a purist, and I'm more worried about melting the rubber parts on the YICS tool than being perfect. I worried about the valves and bought the valve tool, and finally (after about 3 hours!) gave up and used the bent wire method and finished in about 15 minutes. Besides, I'm a cruiser, and I still haven't had this bike over 7000 rpm.

 

Yeah we've beat this horse enough.

However, if "close enough" is ok, then fine.

That being said, if you sync without blocking YICS, the "attenuation" from the other cylinders' YICS passages can and will "mask" a slightly out of sync condition.

If you sync without blocking YICS and the bike seems to run fine, ride it. If you then discover you're getting poor fuel economy compared to what you should be getting, go back and follow the factory-specified procedure (sync with YICS blocked.)

Personally I just follow the book to begin with.

 

Aww crap, so I wasted my money buying the blockoff tool?! I was reading how to do it here and everyone was causing a ruckus about how much it was needed...

 

Know this: On the 550s, those YICS passages are much LARGER than they are on the bigger motors.

As a result, they represent a MUCH LARGER "percentage" of the intake tract.

Sync a 550 without blocking YICS and see where it gets you. It WON'T get you 52~56MPG.

You gotta do it right for that. (I've tried it both ways.) You didn't waste your money if you bought the proper tool; you just have the opportunity to do the adjustment as recommended by Yamaha.

Or not.

Your choice.