470 conversation tuning

[ANGELO]

Went out for about 2.5 hours today's. Mostly cruising but I did have some wot running dry and some idling.

Port right is rear


Rear cylinder is definitely burning oil.


Stbd right is front.

What makes it run richer the further from the carb it gets?

It seems to perform almost the same as before, except I noticed significantly less fuel burn.

 

[John Fenner]

I'd say #5 is burning a bit of oil for sure, #2 shows lean but not bad on the rest, this might be plenum design or #2 is just stronger than the rest or intake hose or flange seal leak.
Swap #5 plugs to #2 to clean them.
Gotta remember that there was a lot of fuel being dumped to it before, could've washed the rings on #5 causing the oil usage.