XJ750 YCIS carb synchronisation

Good Morning everybody question?

I have a mercury manometer, and I want to sync the carbs on my new bike. However the Haynes book says that for YICS models I need to have a "blanking tool". Can anybody out there explain this to me, what it is? what it does? Do I need to use one?

Any help would be great!! Thanks

 

yes, for the best results you should use a yics blanking tool.

You can build one yourself, with common DIY materials.
Please use the forums search function on "YICS" for a build manual.
there are various topics spend on this one

I did the last time carb syncing in two steps
- benchsync (search for this)
- running sync... just listent what the engine told me...

 

The YICS system lets air transfer between the four intakes. If the system isn't plugged up your results are unreliable.

Many of the DIY drawings floating around are missing the seal on the handle end - allowing leakage to the #1 or #4 intake depending on whether you insert the tool from the left or the right.

Chacal sells a nice one.

 

Here it is!:


vv7) 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!

HCP5460 reproduction YICS port blanking tool.

 

where can i find a yics blanking tool

 

Since you're supposed to "clean-out" the YICS passageway before using the $37.00 tool, there's no loss in using the "oily rag" method the first time, which is basically free.

To un-cram the passage, I used a chevy pushrod & hammer and just drove the plug thru.

 

That would be XJ4Ever, or PM member chacal, proprietor and the author of the post from 2008 JUST ABOVE YOURS (scroll up or see below) he still carries them...

 

how can you be sure that when you push whatever through the passage that your not pushing crap up into the little ports?

 

He was referring to an oily t-shirt "rope" I do believe.

Hopefully, if the passage was clean beforehand, said "crap" would only be some oil, and if that's the case, "up" is the solution-- what goes up must come down, and if it's only some oil it won't take long.

I prefer using the proper tool in a clean passage.

And boy did THAT sound bad, double entendre-wise.

 

how about one of these.
what is the proper tool?

 

That would be a good question to ask about ANY tool - - would a rifle bore brush inadvertently shove a bit of sticky carbon mess into the transfer ports??

Do we now have to all buy Chacal's "Port-Picker"??


c5) Yamaha YICS PORT CLEAN-OUT TOOL----the YICS chamber runs side-to-side in the back of the cylinder head, and is accessed via a 12mm bolt on either end (this is the same chamber that the HCP93 synch passage-block-off tool fits into). This chamber has four tiny passages in the top, one for each cylinder. These passages can accumulate soot and other material over time, effectively clogging or reducing their capability to pass the fuel-air mixture through them, and thus compromising their function. This YICS port probe & clean-out tool has a spear point that can punch through the toughest accumulation of carbon build-up, and has marked notches on the extension rod to indicate exactly how deep into the chamber the tool must be inserted to easily locate the passages. Convenient dowel handle allows for ease of use. A very handle tool to have around! For use on all XJ650 - XJ1100 YICS-equipped engines (not needed on XJ550 engines).

HCP1282 Aftermarket YICS chamber PORT CLEAN-OUT TOOL:
$ 14.95