YICS, ColorTuning and a new tidbit that may answer

some of the problems some of us have been experiencing trying to ColorTune.

Now bear with me here... when we use the ColorTune, we're doing basically the same thing that was originally accomplished by the factory or dealership using an EGA, that is, fine tuning the mixtures.

I've been reading the Yamaha EGA manual (thanks Len.)

First tidbit (and we've covered this Yamaha specifies the use of the YICS port blockoff tool for the entire carburetor tuning procedure, including EGA mixture adjustment (which we're substituting with ColorTuning.)

Possibly important new information: Preparing to do the EGA test, in addition to warming up the motorcycle (to an oil temp of 126*F-163*F) and attaching the EGA equipment, Yamaha says to:

"Remove the crankcase breather hose from the air box."

It gets better, still directly quoted from the manual:

"Oil Contamination Check
When the idle check has been completed and all adjustments and repairs made, reconnect the crankcase breather hose and watch the EGA meters. If the CO reading increases more than 1% (except on XS650s, singles and V-twins), the engine oil is contaminated and should be changed. If reconnecting the breather line on XS650s, singles and V-twins causes rough idle, the oil is contaminated."

This is all very interesting. Now I wonder (and I'm going to find out REAL SOON) if the breather being connected to the airbox makes a difference while using the ColorTune. It stands to reason that if the EGA can be affected by the breather, we might also be thrown off by it on our visual substitute, the ColorTune. The breather wouldn't be mentioned in any of our service manuals, because none of them have us messing with the mixture screws.

I never considered disconnecting the breather but it makes perfect sense.

 

Interesting I'm getting ready to do a colortune/sync in the next hour or so. I'll have to try that. Great timing Fitz!

So Yamaha is saying we should colortune with the YICS blocked too? Interesting...

 

Yamaha didn't know about the ColorTune; they used an EGA. WE'RE using the ColorTune to accomplish the same thing only visually (adjust the mixture for proper combustion.)

Yamaha specifies using the YICS blocking tool AND removing the breather from the air box when doing the EGA procedure. It stands to reason those same parameters would apply to our "substitute EGA" the ColorTune.

So yes, but indirectly.

 

Fritz could it be that they were tuning to meet an emission standard with a much more sensitive instrument than what we have. Would we not want to tune with the breather hose attached as this is the condition which the engine will be exposed to 99.9% of the time. Having the hose hooked up could make a difference because of the positive pressure being pushed into the air box. If the oil was contaminated with fuel vapor the EGA might pick it up but I don't think we would see it on the color tune. Can't wait to see what Bill finds out.

 

Yeah thats definatly interesting. I'm saving this post onto my favorites for future referance. Definatly need to buy a YICS and a colortune like asap. Let us know what you find Bill! I'd love some answers
-SLkid

(Edit) Fitz, are you supposed to remove the breather when you Sync AND Colortune?

 

I don't think you would need to remove the breather for sync; that's a vacuum thing at the manifolds. The factory service manual never mentions it for sync (and they use a 4-stick manometer.)

You're 100% right about the EGA being a damn sight more sensitive (and accurate) than us trying to "read the flame" but we are trying to accomplish the same end.

Even with HORRIBLY contaminated fuel, I don't know if it would make a visible difference or not. It's also possible an older motor with some blowby could put enough into the breather stream to affect mixture tuning, I honestly don't know. This whole thing is uncharted and undocumented territory.

My whole reason for sharing the information is to try to strip some of the secrecy from the "we set these at the factory don't touch them" mixture settings. The more we can learn about it the better. I wonder how much a small EGA costs these days... where's my Northern catalog?

 

OK guys here you go - Fitz I got the Colortune EGA thing I was extrapolating.

So I colortuned my #1 without the YICS tool and with breather attached. Then I Put in the YICS tool and removed the breather.

It got richer by a few degrees.
I put the breather back on - no change (expected unless there is fuel in the oil).

Removed the YICS tool and you could see it was a few degrees leaner.

So I wound up colortuning all 4 with the yics tool in and they did a sync.

Interesting results it certainly does make some difference. When I get back on the road I'll check the plug coloration and see where we are.

 

I don't disconnect the Crankcase Hose.
I DO do the Colortuning ... Twice.

First time WITH the YICS Tool IN and Tune for BLUE "On the Back-end"

Then, I see how the Bike performs out on the Road.
Invariably, the Colortuning will be LEAN for Wide Open Throttle running.

So, to save myself the Step of learning that the Colortune is LEAN.
I do a Second Colortune.
A "As you'd Ride it TUNE."

Individual Carbs.
Colortune WITHOUT the YICS Tool.
Colortune TWEAK.
Go from LEAN ... into BLUE ... Slowly through the BLUE ... and, right to the Spot where the Blue gives way to Slightly RICH.

Why?
Because if you Colortune to the BLUE ... you have the right Mixture for a perfect IDLE ...
But,
NOT enough RICHNESS for OFF IDLE Acceleration to be keen.

The BLUE is a Perfect Combustion Mixture.
The Mixture YOU NEED is slightly MORE RICH then the BLUE shows.

But, NOT VERY MUCH more.
Just past BLUE.
When the BLUE begins to be LESS Bright.
Run that.

Then, just TWEAK it by examining the Plug Color after riding.
You may be either On-the-Money ... Or, just Slightly LEAN ... depending on the Condition of the Engine's Condition.

If your Compression is Good. The Mix might be a HAIR Lean.
Lower numbers in Compression will allow some extra OIL Sheen to be present and added to the FUEL ratio ... putting you right where the Bike will be running Cool and quick.

 

Rick your procedure describes how I usually tune ( at least the part about without the YICS) It seems you see the same thing I observed - with the YICS it tunes you a bit lean.

Most of the time I feel like I'm on the rich side (maybe a bit too much) I am not quite recovered enough to take it out at highway speed but as soon as I can I'll report back.

 

The color tuning I do on the XS1100 is very close to what Rick describes. That engine likes to be just a tad to the rich side or just turning orange. I think the older machines with out the YICS all like to run that way. When I did the last color tune on the 81 650 I could not get as rich as I wanted. Hence the change to the Canadian jets. The mileage per gallon has dropped a little but the color tune is fully adjustable and the bike has no stumble or hesitation off idle.

 

Is it 12 or 14 MM for the XJ650 colortune plug? Which set of sync guages are you using? Reason Im asking Is I Need to do this with my bike and have never done It so Im trying to figure out what to buy and no one In my town has ever heard of this bike or how to tune apparently.

 

I've come up to three repair shops now that "have never heard of these bikes". OF course, doing some asking around with judicious questions leads to the truth of "we're gonna say we never heard of these bikes simply cuz we don't wanna hafta work on some old bike cuz we make a whole lot more money working on the really expensive ones that keep breaking down, etc....blah, blah, blah." Fortunately for me, there's a yammy dealer just down the road who is willing to work on my XJ's because those are what he cut his teeth on. (Funny, he refuses to work on any viragos, though. )

 

I know the 550s take a 12mm, and I believe the 650 is the 14mm but please wait for a 650 owner to confirm.

Sync gauges come in a wide variety (and price) from two empty water bottles half full of ATF connected with rubber tubing; a single vacuum gauge moved from carb to carb, a bank of gauges, or a manometer (sticks) containing either mercury (old tech) or stainless steel sliders (new tech.) Depends on what you want to spend vs. how much hassle you want to go through.

Most shops won't work on our bikes; a LOT of those that will don't have a clue and just want your money. Finding someone who actually knows what they're doing is a challenge, hence the DIY attitude here.

The guy down the road won't touch Viragos because he doesn't want to be the one holding the bag when the starter clutch frags itself. (Not an "if" it's a "when.")

 

650 is a 14mm. I bought a cheap vacuum gauge at Harbor Freight.

 

The xj650s take the 14mm.

 

Thanks for the helpfull replies. I think I will be ordering a 14mm colortune plug. Now I just have to figure out which meter/guage I want to go with and where to get them.

 

Man, every single time I think I got this tuning thing straight in my head ya'll come up with more and more stuff to second guess myself!
I think this is why they have something called a Standard Procedure. Cant wait to get my YICS and Colortune

 

The more we can learn about the "secret" carburetor stuff the better. I continually research and poke about, you never know what tidbits you can uncover. The 550 Seca Assembly manual has an incredible amount of interesting detail revelations. The Yamaha Exhaust Gas Analysis manual while admittedly rather dry reading, has some interesting little factoids buried in it. I'm just the guy that opened the crypt...

 

Should we start calling you the crypt keeper?

 

So here is an interesting tidbit. I just got to put a few miles on the bike (still covering from my fall 4 weeks ago believe it or not - Rib injury is painful and slow)

Anyway as I mentioned I colortuned with the YICS and then did a sync. From my previous experience and Ricks comments I expected to be a bit lean. The bike is running great and felt fine during my ride. Last night I pulled the plugs and to my surprise I had the best tan I have achieved so far. Not sure what that means overall but I believe I will be colortuning with the YICS from now on.

 

Shazam.

 

I have been putting off buying a a colortune and have been struggling to get my mix right, I now realize i have to buy one!!! Am i the only one who is struggling with tuning??? I have worked on alot of engines, of all sizes and NOTHING has been this difficult!!!

 

The color tune just makes it worlds easier since you can see the combustion

 

Ahem, Fitz. Don't you mean


Shazzagum!

haha