Author
|
Topic: 4 corner idle
|
Mpcoluv Gearhead Posts: 1341 From: Charlotte NC usa Registered: Apr 2001
|
posted 10-22-2002 09:34 AM
How do you adjust idle mixture on the 4-corner idle carbs? Just like a standard 4150? Close the rear ones and adjust the front first, and then open the rears?
IP: Logged |
Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
|
posted 10-22-2002 10:56 AM
Pretty much. When done, reset the base/fast idle. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!"
IP: Logged |
MDF99 Gearhead Posts: 234 From: Hamilton, Ohio, USA Registered: May 2001
|
posted 10-22-2002 02:34 PM
What is meant by closing the rear ones? Do you mean turn the carb. upside down and back off the secondary butterfly adjustment screw all the way, then tune the primary mixture for max rpm and vacuum, after which you would re-open the secondaries and set that mixture? Where do you set the secondary idle screws while those butterflies are closed and you're tuning the primaries? Please elaborate.------------------ Matt Fraley 1966 Mustang Coupe; 289, T-5, 9" 3.50 http://mdf99.tripod.ca/289_Side.jpg
IP: Logged |
Just Strokin Gearhead Posts: 754 From: Tuscaloosa, Alabama Registered: Dec 2001
|
posted 10-22-2002 03:17 PM
Closing the rear ones means turning the idle mixture screws until they lightly seat.I have adjusted 4 corner idle mixtures by starting at 3/4 on all four and decent idle and then adjust each screw. Seems to work fairly well.
IP: Logged |
Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
|
posted 10-22-2002 03:25 PM
Yes MDF. Either invest in a tinny jewlers screw driver or remove the carb ans shut the secondaries (depending on the carb. dominators can be adjusted right side up. Adjust the mixture screws on the primaries, then repeat the proceedure for the secondaries. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!"
IP: Logged |
Mpcoluv Gearhead Posts: 1341 From: Charlotte NC usa Registered: Apr 2001
|
posted 10-22-2002 04:09 PM
quote: Originally posted by Moneymaker: Yes MDF. Either invest in a tinny jewlers screw driver or remove the carb ans shut the secondaries (depending on the carb. dominators can be adjusted right side up. Adjust the mixture screws on the primaries, then repeat the proceedure for the secondaries.
Ar you saying that you close the secondaries and cover the idle transfer slot?
IP: Logged |
MDF99 Gearhead Posts: 234 From: Hamilton, Ohio, USA Registered: May 2001
|
posted 10-22-2002 04:11 PM
While you've got the secondary butterflies fully closed and you're adjusting the primary idle mixture, where should you have the secondary mixture screws set? All the way in (leaned out) or should you have them turned out? If they should be turned out then how many turns?
IP: Logged |
Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
|
posted 10-22-2002 04:36 PM
Yes MPC. MDF, you need to invest in either a vaccum guage or a good dwell tach. That will aid you in making the adjustments as accurrate as possible. This is not something that has universal instructions. All engines require different adjustments. Screw them all the way in (one at a time)first, then slowly begin turning them out until you get the highest idle (rpm). Repeat the other side, then front or rear. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!"
IP: Logged |
MDF99 Gearhead Posts: 234 From: Hamilton, Ohio, USA Registered: May 2001
|
posted 10-22-2002 09:21 PM
Let me re-phrase, what I'm trying to get at is this: ONLY DURING THE TIME PERIOD that you're adjusting the primary mixture screws and you have the secondary plates totally closed, where do you want to have the secondary mixture screws TEMPORARILY set so that you get the primary mixture set properly? Sorry for the confusion. Do they need to be twisted all the way in or how much out during that time period? Thanks.
IP: Logged |
Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
|
posted 10-23-2002 01:41 AM
Yes, and try about 1/2 turn out as a baseline. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver MCA member# 53321 NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Professional Manwhore The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked." Quote #2: "Make sure brain is in gear before engaging mouth!" Quote #3: "If you can't run with the big dogs, stay on the porch!"
IP: Logged |