Regardless of where the vac hose is (I assume it leads to the petcock shut-off),
you're gonna need to remove all of the manifold screws/nipple-covers.

The sole purpose for them is to allow you hookups for the sync-gauges.

You may need more or less adapter nipples to screw into their places
(so you can connect the vac-guage hoses). Normally, Honda uses 5mm adapters (I believe).
Use the barbed hose adapter(s) the same size as the screw(s) you removed.

You don't remove the screws on the carb-bodies, you adjust the vacuum with them.
The body without an adjustment screw is usually the base carb, so you adjust to it.
In this case the #3 (according to the manual above).

I would replace the o-ring you lost. Try a hardware or auto-parts store,
bring one, off of another pilot screw, to match up.

Hope this helps with the confusion.

 

Thanks for the info cc rider ;

1) I'll get a new o ring from honda, going to risk riding it tomorrow though.

2) Ive made my own carb sync tuner will post a pick.

3) By 1 5/8 do you mean tighten up then slacken off 1 5/8 turns ?

 

Yes, seat the pilots gently, then back off the correct turns.
One turn is 360 degrees of the head not 180.

Just to mention, be careful 'blipping' the throttle too hard, while your gauges are hooked up,
other-wise you risk sucking the fluid into the manifold.

Good luck, Ern

 

Thanks everyone for the advice and info i really appreciate it.

 

Well i finally got a new o ring fitted, also had to buy some manifold adapters for my homemade gauge and set about tuning my carbs. Heres before and after photos;