New owner of a Morgan Carbtune Pro

Just got it in today so in the middle of the hottest day thus far I'm out there adjusting the sync & colortuning the 650. My old set of four tubes with Mercury were an accident waiting to happen so I got the carbtune so I now can do frequent guiltless and easy checks and adjustments on it.

Glad I got it and no operational issues except when I would blip the throttle to see where the rods went back to, I'd see different readings than before the blip.

Think there is something maybe worn in the spring mechanism around the adj. screws. Eventually I got everything liner and the same height and it ran better than great. Awesome is more like it

I am finding the XJ-CD tool to close off the YICS port is suffering wear in that I may be tightening it too hard to assure sufficient baffling effect. Might be better off with softer high temp rubber tubing.

I think the bike is pulling now much harder than yesterday. I'm glad I got this machine, it will keep me right on top of the tuning and will prolly get better mileage & a longer lasting engine if nothing less than better performance.

 

I LUV my Morgan Carbtune Pro

Cheers, Murray

 

Me too, you can get the bike idling like a sewing machine. Why be "close" when "precisely matched" is so easy?

 

Just one question.. When you get your machine "idling like a sewing machine" then pop the revs and get different readings on each cylinder.. what does that tell you?

 

Not sure what you mean. Different reading while revved up? Or different after they all return to idle again?

 

Just out of interests sake, what's the answer to both questions?

Simplyfying a little, I know that the pilot jet provides a constant flow of atomised petrol to the engine, and the idle mix screw adjusts the amount of petrol the pilot jet lets into the engine, and the amount of air allowed in is managed by the butterfly valves when "closed", which constitutes the idle mix, and the plunger and needle manage the main jet mix which (I think) is what provides varying amounts of power while you twist the throttle.

What I don't understand is why there would be different readings on each cylinder and why they would be different when returning to idle.

Oh, and while I'm at it.. Why does test number 3 on the colour tune chart show the mix burning too rich at higher revs? I thought it might have been increased air flow at speed compensating, but given the position of the air box, I'm not convinced..

Sorry for the questions, but as my old man said, "If you don't ask, you'll never know"..

 

I can't answer primarily because I haven't had the issue, except while doing the balancing, and one or more was still out of whack.

I can say that with the YICS tool installed, the CarbTune is reading each cylinder separately, which is why we use it for adjusting in the first place. There are different readings because each cylinder is producing a slightly different amount of vacuum, which we can now see, and is once again, the reason for tuning in the first place.

With my ColorTune, I never really used "the chart" just back out until starting to "lose" the blue, then back in until JUST solidly blue.

 

Interesting..

The things I read here are that you should go to yellow then back until just into solid blue..

After reading elsewhere the benifits of the YICS tool, I decided it was worth doing it properly and stuffed my own YICS tool into the hole.. A tight fitting t-shirt. It did the same job, blocked the holes so that the cylinders weren't "talking" to each other.

What is interesting is what you said about each cylinder creating a different amount of vacuum.. Because that really explains why you get a different reading at higher revs.. The effect of the differencesis amplified by the high rev count..

I'm guessing you don't balance using higher revs because you're opening the butterfly valves as you twist the throttle, and it's those same valves that you're opening or closing when you're balancing.. Kinda difficult to get an accurate reading when you're using two mechanisms to change the same thing..

Thanks Fitz.. Believe it or not, you've answered my question.

 

I did an experiment & compared my old home made manometer using two "U" shaped tubes filled with mercury which I leveled them out with no vacuum and then with vacuum, ran the suction in all 4 carbs to parallel with the no vacuum reading, with the Carbtune Pro.

The home made one worked pretty well but I found enough difference I can say the carbtune does a better job in all ways. I can hear/feel the difference.

That... and the colortune...

Nice!

 

I have the Motion pro sync tool and one thing I hate about it is that it has to be calibrated at the exact point where the fluid will be when attached to the carbs. If the fluid is raised higher or drops lower than that point, it's out of calibration. Does the Morgan tool share that characteristic? If all the vacuum lines to the tool are tied together and connected to a vacuum pump, do the readings stay the same relative to each other throughout the range? I'd love to know.

 

The newest Morgan uses stainless steel "slugs" in the tubes not liquid, and works great.

Can't answer your question from experience but I believe it would. It doesn't require "calibration."

 

So if you did attach all the lines together and plugged it into a vacuum source, they would all show exactly even?