Carb sync issues

[Vincent Maxwell Ribaldry]

So I did the shot gun method.

The brass plugs had already been removed. Diaphragms are black, no felt around the edge. They look to be in good shape, no holes, guessing they have been replaced (thoughts?).

Counted mix screws in 1/8th turns (19, 24, 22 and 19). I set them all to 19 1/8th turns out after the shot gun. Afterwards I did some research and I turned up that CO testing the exhaust could have been the reason the screws were set differently, bang head.

Still seems to have improved throttle response.

With a 2 bottle sync tool I made.
I sync'd 1 to 2 was a little out
I sync'd 3 to 4 was a little out
1/2 side pulling hard from 3/4 side. Tried syncing 1 to 4 , 1 to 3, 2 to 3 and 2 to 4. No luck, just shit the bed every time.

When I turn the screw counter clockwise it stalls out. Seems like 1/2 side is pulling vacuum hard.

Tried adjusting idle screw and now it just seems to stall. When I turn the screw clockwise the idle is really high adjusting idle screw does nothing.

Was on the right path but not getting anywhere now.


So I guess my questions are:

1. Should I buy a CO meter and a Carbtune 4?

2. Am I in the right neighborhood with the mix screws at 19 1/8th turns for Michigan, elevation 584'.

3. With a two bottle manometer set up, which ports on the carbs do I hook up to balance the right to the left side? 1 and 4?

4. What is the easiest way to get my bike running decent now that I have it fairly well jacked up?

Wanted to go for a ride today, any help would be appreciated.

Thanks,

Sean

 

[1st Shirt Maxer]

Well, if the carbs are stock you can reset the a/f screws to 2 1/2 turns out as a good starting point. As for the carb tune or other gage setup, I bought a carb sync gage set off Amazon for about $80. When trying to sync the carbs you will sync 2 to 1 first. One is always your baseline and cannot be adjusted. Once 2&1 are synced then you sync 3 to 4. Then you sync 4 to 1. If the carbs are stock this should get you back on the road, hope this helps.

 

[Vincent Maxwell Ribaldry]

The carbs have 147.5 main jets, trying to compensate for crappy cobra exhaust.

Your sync advice sounds like what I did initially.

I guess I'll take another stab at the mix screws and see what I come up with.

Also, still smelled real rich at idle before I sync'd. I did have the bike good and warm too when I was trying to sync.

This is my first go with carbs, the only thing I have done before it's change the jets.


Sean

 

[Diablotin]

Downsizing the main jet for running the cobras is a good idea however it should not have any impact with your sync since the main jet will mostly impact your top end power.
As said get a balancer for accurate result (carbtune is the best) and try to sync again after setting all mixtures at 2.5 turns.
Turn in the screws until you feel the bike start to stall.
The raw smell at idle will most likely comes from your float being off. Check the carb section on how to set the dry and wet level.

Start with the float level, then the mixture, then sync when you are done.

Everything is in the carb section on the forum but not sure who is still running with cobra exhaust.

Sent from my SM-N9005 using Tapatalk

 

[dannymax]

Carb orientation:

front

2 4

1 3

rear

#2 is the master carb

sync #1 to #2

sync #3 to #4

sync #3 & #4 to #1 & #2

 

[tugla]

2. 5 turns out should get you decent to go riding along with the sync....

 

[Vincent Maxwell Ribaldry]

Got it running ok. Not any better than when I started, guess I'll do the whole thing over and include setting float height. Thanks for all the info, got me on the road again.

Sean