sen2two

iTrader: (10)

I got the car with the carb basically fully stripped down to almost nothing. I'm running premix so the oil injection ports have been plugged as well. The car is not running yet but it will be by this weekend (hopefully). The last thing to do is cap off and plug up all the unused unneeded ports on the stock Nikki carb, and run the two lines to the distributor for vacuum advance.

I guess my Googling skills suck, or I just or it doesn't exist. But is there an exploded diagram pointing out all the ports needed/not needed on the carb?

t_g_farrell

iTrader: (1)

The only line to use for vacuum advance is the second from the front on the drivers side of the spacer under the carb. The rest are unused and get capped. Then theres the vacuum needed for the brakes that comes off the back of the intake manifold (I think).

Foxed.ca for manuals if you need picks.

chuyler1

iTrader: (1)

If you are running a stripped Nikki (or any carb for that matter) and you've deleted the rats nest emissions solenoids, make sure you set the timing with the vacuum advance lines disconnected from the distributor and the port on the carb plugged. The vacuum advance connects to "manifold" vacuum source but the solenoids, via the stock control unit, are designed to disable advance at idle and while decelerating. If you don't have those solenoids and you're trying to set timing with the lines connected, you'll actually end up with timing that is far too retarded at wide open throttle when the manifold has no vacuum. Ideally, you'd want to connect the lines to "ported" vacuum but I'm not sure the Nikki has one of those. Port vacuum would come from an inlet just above the throttle butterflies. At idle, it would provide no vacuum, at light throttle it will provide max vacuum and max advance, at wide open throttle it will again provide no vacuum and no advance.

t_g_farrell

iTrader: (1)

Actually on the nikki spacer the second port back from the front only supplies vacuum off idle, there is no vacuum at idle. So you don't have to disconnect the advance at all when doing timing. I had verified this with my trusty vacuum gauge when doing my fat nikki a few years ago.

chuyler1

iTrader: (1)

Ahh good to know, I have only checked the vacuum with the solenoid still connected. So what purpose does the solenoid actually serve then? If it's port vacuum it'll disable the advance at idle, and in theory should also disable it during deceleration since the throttle will be closed.

t_g_farrell

iTrader: (1)

Who knows, it probably adjust the advance for emissions in some way.