Stan, I'm with you but I've got it it now so need to persevere.
I was using the centre pivot linkage that Raby's sold when l ordered the Dtm many years ago. I did find that good in the last engine set up. For curiosity l did shelve the Sync recently and put the Raby unit back on and noticed the Sync was much smoother even with this problem. So I'm back with the Sync-Link again.
So putting that aside, this problem I have once the carbs are dialled in at idle without any linkage connected. As soon l move it of idle which l used a washer to hold both carbs exactly the same from idle. I'm getting differant readings, 12 and 18. If l pull the washers the carbs return to idle and both read 5 on the Snails. If l put the washers back in place and adjust bringing the 18 down to 12, once l pull the washers and it returns back to idle they're out of sync and runs uneven.
In the past I've always sync'd them at idle and left it at that. Presuming the'd be synced of idle also. So can be causing this and what can l adjust to keep them sync'd both on and of idle???
I did think maybe its down to differant compression on both banks. So l took a reading and got these. Could it be the 5psi causing this??
Cylinder 1 140 psi
Cylinder 2 135 psi
Cylinder 3 135 psi
Cylinder 4 140 psi
One other thing that I've not tried as I'm writing this is the Air adjusting screw??. Would this be an option?? If not I'm stumped, and any input or direction to go in would be greatly appreciated.