Gunson Color Tune AVI Clip....

Isn't the engine supposed to be a little rich at idle...? For cooling purposes?


according to mikuni (i think thats where I got this...)

..Or is this whats happening here, when you tune this way, at idle...

I confuzzled! :laugh:

The problem I see with your diagram is you have to be at cruising speed for the correct 14.7:1 mixture to be obtained ....

You want this at idle and throughout all your ranges...

Excerpt out of the color tune literature...

I ordered a colortune from Morgan Carbtune , the same place I bought my carbtune from.
I order it on the 17 of April and it showed up today, Apr.27.
56 dollars including delivery.

Yup...

Did you get a MORGAN Carb Sync (vacuum) as well, if so, You're really going to love that MORGAN unit.....

Old Man Rock wrote:

The problem I see with your diagram is you have to be at cruising speed for the correct 14.7:1 mixture to be obtained ....

You want this at idle and throughout all your ranges...

WOW! Theres alot of diferent opinions out there on the internet... my mechanic had all sorts too.
So I'm told now, my diagram above is wrong for idle and WOT, by more than a few people.

So with this setup, your achieving stoich throughout the entire throttle range.

More and more, I'm hearing that a AFR of 12-13 is what will achieve the most HP at WOT.

...but, I don't know.:blink: Is that what the colortune thingy is helping you do? Or just stoich? Maybe I should be asking MORGAN! :woohoo:

...my 2 cents... this would keep things VERY clean inside that pretty engine... how often do I WOT? not much.

I purchased a morgan carb sync a few years ago. It works well.

Tek9....

Is that what the colortune thingy is helping you do?
Exactly! At idle, you're calibrating your carbs for the correct mixture at idle which works throughout your entire range.

As you hit the throttle you'll see the ignition flame go predominantly yellowish which is expected for your adding fuel :ohmy: :woohoo:

Of course, (entire range) also depends on ideal/correct jetting...

NOTE: Via keihin literautre in my case, find the ideal jet configurations for hp then go up one size in main jet! Translation, you want to be more rich then lean!!!

Or just stoich? :huh: :dry: :blink: :laugh:
Not sure what this is.....

Is this polish humor or something? :laugh:

It's been about 20 yrs or so since I studied that and my memory isn't as good as it used to be but Im pretty sure he's referring to Stoichiometric Combustion. It's the ideal combustion process during which a fuel is burned completely.

:laugh: Yeah, Stoichiometric is what I meant. 14.7:1 Air:Fuel Ratio.

OK, I think I get how this thing works now. I'd like to tinker with one myself.

I think I just might wait and get a Wideband O2 sensor setup later... maybe.

:huh: :dry:

Redneck Rejet: Duktape or some o da arr felter to "richner' up" :laugh: :woohoo:

Cheers an thanks.

Came across a different/better GUNSON color chart for tuning....

Take note of the second test procedure.... Ahhhhhhhh!
Now this made a difference where previously, a slow twist would still leave me a little yellow where it should stay bunson blueish.....

Thanks OMR...

I tried to read this on my screen and then tried printing it on my laser printer and reading it... but it was not clear enough for my vintage eyes.

Any chance of getting a really high resolution colour scan and putting it in a convenient place here on the site?

Looks a lot better than the instructions I recently got with my new Gunson Colortune. Too bad they cut back on their documentation quality like that.

Best of success.

Hey Bill...

Ask and thee shall receive...

members.cox.net/ruinsofstei/Color1.jpg

members.cox.net/ruinsofstei/Color2.jpg

OMR