Syncing Left and Right Carbs

[walktheline]

I started to sync the carbs this morning and I got 1 & 2 synchronized, and 3 & 4 synchronized, but I ran out of play on the L - R sync adjustment. Any Ideas? Would a sticky V-boost cause this? I do hear the servo actuating when I turn the bike on.

Brad

 

[113s&s]

never sync my carbs yet put how did you sync number 2 carb though you only sync 1 ..3 and 4

 

[dannymax]

never sync my carbs yet put how did you sync number 2 carb though you only sync 1 ..3 and 4

#2 is the master carb, it has no adj screw. You sync #1 to #2, then #3 to #4, then #3 & #4 to #1 & #2.

danny

 

[walktheline]

#2 is the master carb, it has no adj screw. You sync #1 to #2, then #3 to #4, then #3 & #4 to #1 & #2.

danny

That is the order that I followed, it is the last step that I am asking about, the 3 & 4 to 1 & 2, sorry if I did not explain my troubles adequately.

Any ideas???

Brad

 

[Storloc]

Im definately no carb guru but there are three tension springs, one per adjuster, that are installed right behind the sync adjuster screws. The only thing holding them there is a raised boss on one end. I would look to see if those are still there. See picture.

 

[walktheline]

I went out at took a look, all of the springs are still in place.

 

[maleko89]

Make sure no air leaks and the carbs are fully seated in the boots and clamps tight.

 

[walktheline]

I did check to make sure there were no leaks, even took a little starting fluid (eeks) and sprayed around the boots - everything looked good.

 

[walktheline]

Here is some more info:

I am using a motion pro to sync the carbs, it does not have any values on the column (of course it is all relative since you calibrate it to one cylinder) so I used a vacuum gauge to measure the vacuum at ~ 800rpm idle.

Carbs 1 & 2 - 4.5 - 4.8"
Carbs 3 & 4 - 6.8 - 7.0"

This is with an old vacuum gauge ( I used one of the lines off the motion pro because I needed the restrictor to get a good vacuum reading). It is idling smoothly, has a little hesitation when you blip the throttle.

When I synced the carbs I had the idle at ~1200rpm (I have not measured the vacuum at that speed).

Brad

 

[Storloc]

I usually set sync at or below 1k rpm. Might give that a shot.

 

[walktheline]

Would the idle screws have any bearing on the vacuum at idle? I am thinking that the screw just determines the mixture, but would not necessarily decrease the vacuum.
I hooked the sync tool on at a 800 rpm idle, the results were the same, the right cabs are in sync and the left are, but there is a difference between the sides.
Thanks everyone for your help thus far.
Brad

 

[maleko89]

It does a little bit. If you richen vacuum goes down a bit, lean it (screw tighten) and vacuum will raise a tad.

 

[Storloc]

If it were me I'd be thinking about a cleaning session at this point. At the very least a "shotgun" just to see if that helps any.

 

[walktheline]

OK, whats the deal with the peashooter and the shotgun - I have seen mention to this in several threads:ummm:
I went to the idle circuit cleaning sticky thread, but the link is dead.

I have 1/2 can of seafoam in the tank now.

The brass screws are already drilled out, but I have not messed with the idle screws myself.

Thanks for the help

Brad

 

[Buster Hymen]

OK, whats the deal with the peashooter and the shotgun - I have seen mention to this in several threads:ummm:
I went to the idle circuit cleaning sticky thread, but the link is dead.

I have 1/2 can of seafoam in the tank now.

The brass screws are already drilled out, but I have not messed with the idle screws myself.

Thanks for the help

Brad

What link is dead, the shotgun link?

 

[Storloc]

Link is working as of now anyway. Give it another try. http://vmax.lvlhead.com/tips/shotgun.htm

 

[walktheline]

Both links are working now!