Should I up the mains for a 550t with a 4-1 header

[gsrick]

I've cleaned and o ringed the carbs and intakes on a friends 81 550t. I bench synced them and the idle hangs or drops to low. When it cuts out from idleing low, I have to choke it to restart it. It is running a V&H 4-1 header and the stock airbox. It has the stock mains (92.5) and I've turned the airmix 4 out. It is still haveing an idleing problem. Reading a few past threads, it has been suggested that if you go up to 4 turns that you should up the main. Is 4 out too far and time to rejet or can I go farther. Any help will be greatly appreciated.

[Steve]

Start with a vacuum sync to make sure all the cylinders are firing the same.

Four turns out seems a bit excessive, but that might clear up a bit with the vacuum sync.

Should you up "up the mains"? Only if you ever plan on running the bike on the main jet.

When it "cuts out from idling low", is it because of mixture or simply having the master idle knob set too low?
That low idle could be caused by too rich an idle mixture, pull the plugs to verify.

.