Carb Synch - Looking for a better understanding

[BigBear]

I've read a number of threads here that give explicit details on how to synchronize the cards on an RSV using the Morgan CarbTune...basically "make all four of the bars match".

 

Have a look at the attachment for reference.

 

 

There are a LOT of smart folks here, so here goes:

• What is the effect adjusting all of the carbs so that their reading matches carb 4? Does this make things too lean or too rich?
  
• What is the effect adjusting all of the carbs so that their reading matches carb 3? Does this make things too lean or too rich?
  
• What are the net effects of running too lean or too rich?
  

Any facts, conjecture or comments would be greatly appreciated! :confused07:

[Scooter Bob]

You're not adjusting the mixture, but the throttle plate position. You need al 4 throttles acting in sync to feed the same amount of mixture to each jug, so they all put out the same power at the same time.

 

Hope this Helps, Scooter Bob

[Freebird]

I agree. Syncing the carbs is not going to affect how rich or lean the bike is running.

[BigBear]

All the synchronizing process does is ensure all four throttle plates are roughly in the same position (open vs closed).

 

So, what happens if I adjust ALL of the throttle plates higher on the Carb Tune? Does that equate to the throttle plates being more open, or more closed?

 

Seems like the relationship of each throttle plate (more open or more closed) would affect power...based on the air/fuel ratio.

[V7Goose]

To grok the sync process, you must have a better idea what is going on. You cannot adjust any individual carb throttle position by itself. Each screw just changes the connection between TWO carbs, so turning it one way causes carb "x" to open more and carb "y" to open less. At whatever point they BOTH pull the same vacuum, no matter what that vacuum level is, they are in sync. So you don't have a choice of what vacuum level to sync them at. Once they are all at the same vacuum, if the idle speed is too high or two low, you use the idle adjustment to change the opening of ALL of them together, which keeps them in sync.

 

And as others have already said, none of that changes the fuel mixture at all, it just ensures that each cylinder is working equally hard.

Goose

[BigBear]

That's the sound of the light coming on!

 

I knew that the Carbtune was measuring vacuum, and that in turn was being used to synch all of the carbs to same measure of vacuum.

 

What I was struggling with was how the measure of vacuum affected the engine's performance from a "synchronization of the carbs" perspective.

 

So, after getting the carbs in synch, what's the next "logical" step here?

 

I now GROK in fullness"!

 

Thanks V7Goose!

[SilvrT]

So, after getting the carbs in synch, what's the next "logical" step here?

 

 

RIDE ! ... and then RIDE some more !

[raceman62race]

So, after getting the carbs in synch, what's the next "logical" step here?

 

 

Thanks V7Goose!

After you synch carbs you'll need to set the idle speed using the idle adjustment..... then ride