I think if anything the lack of a secondary would give you better mileage at the expense of power. With a non-opening secondary I get 17mpg doing 105kph on the interstate and 14-15mpg in town.Actually NAPA sells one and it was replaced when I rebuilt the carb with the head back this time last year. Not sure what is going on but with it being all of in the 20s and 30s lately I really need the truck. Can't afford to take it down to rebuild the carb and see what is going on. Going to test the HAC when I get a chance to see if it is operating properly.
The secondary not working could explain the horrible gas mileage. Literally dropped from 10-12mpg in town to now about 6mpg. But does a lot better when I do long trips. I had adjusted the timing right before all this started but it was a very minor tweak, maybe retarding it a couple degrees max.
I'd be down for a set.Do we need to have a carb diaphram sale? $10/diaphram if you buy a carb kit?