One quick question on carb syncing

[benzy2]

Looking at getting a carb sync tool and was still just a hair unclear on the readings. I read the tutorial and it says to tune 1 and 2 then 3 and 4 and finally left to right. Sounds simple enough but I still have one or two small questions. Using a gauge I will be looking at numbers. Are these numbers irrelevant out side of being equal? When I look at the design of the carbs it can't see how you could adjust all 4 to a given value. As such it seems like you are stuck with whatever number they balance out to. Is that correct? It seems like a system that should be set to a given spec and not just equal. I am new to syncing but it seems like You should be able to adjust all 4 independantly to set them to a given value. Still trying to make sure I understand what I am doing completely before I tear into this.

 

[gamorg02]

the key is they are all equal. someone with more info can chime in as well, but as far as i know carb1 you cannot change so you synch everything to that.

 

[pianne]

Garret is right. The no1 carb cannot (doesn't need to) be synch'd.
So basically, what you do is get the other 3 carbs equal to that one.

As for a fixed number: there is none. What you read off the synch tool is a vacuum (negative pressure) caused by the piston sucking air in through the (almost closed) throttle valve. As the valve is opened, less vacuum is read.

You can adjust the figure for carb1 by changing idle speed. You'll notice that your idle speed is changing as you adjust the other 3 carbs, never mind that, just get them equal and then set idle speed back to 1000 rpm.

The key to synch'ing is just to get all four throttle valves to open simultaneously.

I hope this explains it a little...

 

[4gasem]

Did you read the guide on how to sync Vmax carbs? They aren't the same as other carbs. The front left one is static, meaning it doesn't change. You adjust the others to be equal to it. It will take some time and you'll have to go back and forth but it's UBER simple.

Chris

 

[benzy2]

Yeah I read the thread on it and saw that you were adjusting to a fixed carb. What I wasn't considering was adjusting idle. The idle adjustment is what gets you back to where you want to be for all the carbs. I was thinking if #1 was way too high or low and you sync the rest to it you would have issues but adjusting the idle back to 1000rpm will get you back where you want to be. I was just a little confused how you adjusted the entire system if the master carb became out of adjustment but the idle fixes that.

 

[maleko89]

FYI, the left-front is the #2 carb.

 

[4gasem]

Ok so you're good to go?

 

[benzy2]

Yeah I'm all set. I picked up the service manual today as well. Between the net and the manual its all covered. I wasn't looking at the instructions to know if #1 or #2 was the master so I may have misspoke on that. Once I factor in the idle screw everything made sense and I'm ready to go. Just need to order the manometer now. I couldn't believe how much the shop was quoting to sync things up. If they really need synced every couple thousand miles/couple months shop fees would get out of hand real quick. Adjusting them seems easier than changing the oil and certainly not something to pay $80 a trip for.

 

[06VMAXIMUS]

The tutorial on this site makes it super easy. I ordered a morgan carb-tune, and the first time I did it, I was thinking.....Thats It???...Its that easy??? Yup, its super-simple. As far as a set reading, I think that engine wear and other factors make that impossible....just make sure they are all close to equal.

 

[4gasem]

I set mine 3 or 4 times during break-in and it needed it everytime.

 

[vmaxride06]

Just synced up the carbs this morning over coffee, she was due.
Spot on now. Last time I did this was the middle of the riding season last year. I think I will increase the intervals to twice a year.

I used the Morgan Carbtube pro, easy as pie.

 

[gamorg02]

i figure every oil change can't hurt, or at least every other... or when my idle speed changes or something....

it'd be even easier if i had a 4-way doohickey but for $25 shipped i'm not complaining with mine!