Carb is bogging under hard acceleration and black carbon out of tail pipes
12-02-2001, 05:46 PM
#1
Team Owner
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Carb is bogging under hard acceleration and black carbon out of tail pipes
Could this be a spark plug problem?? They have not been gapped since I went for electronic ignition back to points.....Thanx
12-02-2001, 07:14 PM
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Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Alwyn678)
Could be a spark problem or mayeb the car is running really ritch. Pull a couple a plugs I'm gessing they will be black. Clean them (or replace) and regap to.35 and see what happens.
What kind of ignition did you have before?
What kind of ignition did you have before?
12-02-2001, 07:44 PM
#3
Race Director
Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Mike69)
I just had a set of plugs go bad on my car. It would bog slightly on light acceleration for a momont then slightly clear up. I hope Mike69 was a typo at .35 gap. It should be .035. Try a set of plugs before tearing into the carb if they have not been replaced in a while.
12-02-2001, 07:51 PM
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Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Alwyn678)
Most likely, your secondary airvalve is set up too loose. This will allow the secondaries to open too soon, and this will pull the metering rods out of the holes, running the engine full rich prematurely. This will cause a severe bog, and black smoke out the pipes. Here is the process for setting up the airvalve:
The secondary spring windup is adjusted with a small, slotted-head screw on the passenger side of the carb, right at the top of the carb on the secondary side. The screw head points right out to the side. 90 degrees from this, on the bottom, there is an allen-head lock screw that keeps the slotted screw from turning. If you have trouble seeing it, place a mirror under the area until you spot it. With a small slotted screwdriver holding the adjustment screw, loosen the allen screw about ¼ turn. This will allow you to turn the slotted adjustment screw. Counting the turns, allow the slotted screw to slowly unwind until all spring tension is gone. You can use your mirror to see the spring disengage contact from the pin lever underneath the air horn. If the spring tension was lost after only ½ turn, the windup was too loose. Bring the spring into contact with the lever. Note when it just barely touches. From this point, wind the spring up between ¾ turn and 7/8 turn. This is a good starting point, and will prevent any bogs or hesitations due to premature secondary opening.
The secondary spring windup is adjusted with a small, slotted-head screw on the passenger side of the carb, right at the top of the carb on the secondary side. The screw head points right out to the side. 90 degrees from this, on the bottom, there is an allen-head lock screw that keeps the slotted screw from turning. If you have trouble seeing it, place a mirror under the area until you spot it. With a small slotted screwdriver holding the adjustment screw, loosen the allen screw about ¼ turn. This will allow you to turn the slotted adjustment screw. Counting the turns, allow the slotted screw to slowly unwind until all spring tension is gone. You can use your mirror to see the spring disengage contact from the pin lever underneath the air horn. If the spring tension was lost after only ½ turn, the windup was too loose. Bring the spring into contact with the lever. Note when it just barely touches. From this point, wind the spring up between ¾ turn and 7/8 turn. This is a good starting point, and will prevent any bogs or hesitations due to premature secondary opening.
12-02-2001, 07:58 PM
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Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Gordonm)
I hope Mike69 was a typo at .35 gap. It should be .035.
12-03-2001, 01:44 AM
#6
Race Director
Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Alwyn678)
Do you have a fuel pressure regulator?....mine is doing the same thing....Bought one for my car....problem solved. :seeya
12-03-2001, 10:09 AM
#7
Team Owner
Thread Starter
Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Alwyn678)
Thanks guys I will start with the plugs to begin with and then maybe try the fuel pressure regualator to see what happens,,,I think that the plugs need changing anyway it has been about 30k on them
12-03-2001, 10:10 AM
#8
Team Owner
Thread Starter
Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (Mike69)
Could be a spark problem or mayeb the car is running really ritch. Pull a couple a plugs I'm gessing they will be black. Clean them (or replace) and regap to.35 and see what happens.
What kind of ignition did you have before?
What kind of ignition did you have before?
Mike I had a pertronix igniton and had sever problems with the ignitor II...backfiring and sputtering
12-03-2001, 10:11 AM
#9
Team Owner
Thread Starter
Re: Carb is bogging under hard acceleration and black carbon out of tail pipes (lars)
Most likely, your secondary airvalve is set up too loose. This will allow the secondaries to open too soon, and this will pull the metering rods out of the holes, running the engine full rich prematurely. This will cause a severe bog, and black smoke out the pipes. Here is the process for setting up the airvalve:
The secondary spring windup is adjusted with a small, slotted-head screw on the passenger side of the carb, right at the top of the carb on the secondary side. The screw head points right out to the side. 90 degrees from this, on the bottom, there is an allen-head lock screw that keeps the slotted screw from turning. If you have trouble seeing it, place a mirror under the area until you spot it. With a small slotted screwdriver holding the adjustment screw, loosen the allen screw about ¼ turn. This will allow you to turn the slotted adjustment screw. Counting the turns, allow the slotted screw to slowly unwind until all spring tension is gone. You can use your mirror to see the spring disengage contact from the pin lever underneath the air horn. If the spring tension was lost after only ½ turn, the windup was too loose. Bring the spring into contact with the lever. Note when it just barely touches. From this point, wind the spring up between ¾ turn and 7/8 turn. This is a good starting point, and will prevent any bogs or hesitations due to premature secondary opening.
The secondary spring windup is adjusted with a small, slotted-head screw on the passenger side of the carb, right at the top of the carb on the secondary side. The screw head points right out to the side. 90 degrees from this, on the bottom, there is an allen-head lock screw that keeps the slotted screw from turning. If you have trouble seeing it, place a mirror under the area until you spot it. With a small slotted screwdriver holding the adjustment screw, loosen the allen screw about ¼ turn. This will allow you to turn the slotted adjustment screw. Counting the turns, allow the slotted screw to slowly unwind until all spring tension is gone. You can use your mirror to see the spring disengage contact from the pin lever underneath the air horn. If the spring tension was lost after only ½ turn, the windup was too loose. Bring the spring into contact with the lever. Note when it just barely touches. From this point, wind the spring up between ¾ turn and 7/8 turn. This is a good starting point, and will prevent any bogs or hesitations due to premature secondary opening.
VERY INFORMATIVE>>>I will check this as well......Thanks for the Insight Lars!!
