Post by JLloyd on Mar 1, 2005 22:39:14 GMT -5
Hi How's it going? I posted a question about a Demon Carb on Moparts.com and it was suggested I come here to ask it. The problem I had was the carb was running very rich at idle, so here's what I did. Oh yeah carb is a 650 Speed Demon w/ vacuum secondaries and a choke. Motor is a 68 340, w/ ported iron heads, cam is 234 @.05, 9.64 true compression. It was suggested that I remove the choke from the carb, which I did, but it still ran rich at idle. I then changed the powervalve from an 8.5 to a 5.5-that made a huge difference. Vacuum read 12in in park. I know I should check it in drive, but I can't do that untill I finish a couple other things on the car. I adjusted the mixture screws to get the highest vacuum reading which left them at about 1 turn out, but it still seems a bit rich idling. Fuel pressure is 4.5lbs and I changed plugs and oil after the overly rich condition so as not to be fooled by fouled plugs. Ignition is an MSD(box and Distributor), timing was set at 18 degrees intial and 34 total, I backed it off to about 16 degrees initial and it idled much smoother and started easier. Once again I have to wait a bit to check it all in drive and I can't road test it for about another month becasue the car is still in the final stages of body work and paint, so... is there anything I am missing, or should I just wait and recheck everything once I get the car ready for the road- at least tunable in drive? Will a rich idle change that much from park to drive with this carb? I like the carb a lot so far and I'm sick of people saying to forget it and get a Holley; to me thats just people not willing to learn how to tune something different, but in order to learn this carb I need some help from people that know them a little more than old Billy Bob and his 1050 Dominator on a fairly stock 340.