Mastered carb sync today.

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assassinx1

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Hey guys Synced my carbs today. Best way to do it is use 4 gauges. I went to harbor freight and bought 4 vacuum gauge's for 40 bucks. Just pinch the lines until it take out the fluctuations. The best way to do this is set your idle to 1200 RPM.

Adjust the right side front carb to match the left front carb. The left front carb has no adjustment thats why you match the front two.

The idle may raise or drop due to this.

Adjust the idle back to 1200 rpm.

Now adjust the rear two evenly until both sides match the front two readings.

my non adjustable carb. (left front.) is set at 10 inches of vac at 1200 rpm.

I was able to get all four carbs to read identical at 1200 rpm. The i set my idle to about 900 rpm and they all read the same as well. its not a full DIY but made life easy when I figured out doing the front two works the best. This is because if you play with the back two or one of the back two it will change the position of the idle and throw off the front two every time you make a change.
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did you sync it with the airbox off??? not shure that was a good idea my friend:ummm:
 
did you sync it with the airbox off??? not shure that was a good idea my friend:ummm:

Double checked after box install itmwas the same. Bike ran beautiful. Felt like a new animal.
 
Did you sync the gauges first?

I installed all four gauges 1 at a time on cylinder 1. The non adjustable one. They all read identical. Meaning they work within the same range. Then installed them on all four cylinders. They don't need to be calibrated like the fluid filled sync pro style gauge.
 
assassinx1,
That's a strange way to sync carbs on a VMax. The way the carb linkages on the Vmax are set, first, after warming the engine up: you adjust cylinders #1 (left rear) to #2 (left front) so the readings are the same using the left side screw adjustments. Second : you then adjust cylinders #3 (right rear) to #4 (right front) so the readings are the same using the left adjustment screw located on the right side. Finally: you use the right side screw adjustment on the right side to balance carbs #1 / #2 to #3 / #4 .

As Rhoy Carter suggested, the guages should be checked for the same calibration first.
 
No worries. As long as all readings are even box on or off and with in spec from what I read on a vmax 8 to 12 inches of vac depending on rpm. ......1200 rpm is the best rpm zone due to the vac you are reading. If rpm to low the vac reading is too high almost in the 30s on some engines.. But most importantly synchronizing is just making sure the butterflies are opening and closing at the same time. And pulling the correct amount of cfm and vac. Which should be even on all 4.
 
Bike is still apart I will do it that way tomorrow. I'm sure it will work fine. And do it with the box on as well. This way worked for me with no problems due to the fact that the right front was so far off spec it helped me get it back to where it needed to be . Before I adjusted all 4. Plus with having the box off I was able to move the slides and see if then butterflies were to far open again to get it back into a range so I could adjust. Not everyone is going to have this issue. I did because when I took the carbs apart to clean them I had to loosen the right front carbs adjusting screw.
 
Ok it was bugging me I went out to the garage I unadjusted everything. I did my method again. Then un adjusted. Did the factory method. In both types of adjusting. Box on. Got the same readings between both methods. The most important thing being all four carbs are even pulling air.
 
You got it pretty sussed out now. A couple of helping tricks:

- if you take a thin metal bar and drill it at the appropriate intervals you can mount all four gauges side by side making it a lot easier to read
- to reduce fluctuations without having to pinch the hoses, cut about an inch length of the inner isolator of a standard TV cable (the white bit) and insert one of these in each of the four hoses. Works beautifully.
 
i like my motion pro...better then the gauges:punk: cept the friggin fluid seems to evaporate outta it periodically:ummm:
 
i like my motion pro...better then the gauges:punk: cept the friggin fluid seems to evaporate outta it periodically:ummm:

That's the great thing about the Morgan CarbTune... it has precision stainless tubes. No friggin fluid to ever worry about evaporating ! :clapping:
 
I bought a motion pro. the fuid kept getting sucket in. Its in the mail headed back to the company lol. I prefer mechanical gauges. The motion pro would have been awsome if they used solid plastic bb's or somthing to move up and down as aposed to liquid. the BB's could stop at the top.
 

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