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73 Starts Easy But Popps Through Carb At Idle, Goes Away When Reved


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Got my 73 going tonight, it starts really easily, but popps back through the carb at idle. I moved the distributor around abit but no change. didnt look at adjusting the points yet. think it might be that? any ideas? 
 
things done to it, new points, rotor, cap, plugs, coil, condenser, carb cleaned etc..
 
Video here: 

Current - Red 73 2K2 with 318i/Volvo 240 EFI. 5-speed/LSD in soon; 2003 Suzuki V-Strom 1000 Motorcycle

In the past, - Burgandy 76 parts car, scrapped.

                   - Green 75, Sold, being restored now by new owner.

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Adjust your point's gap to 0.014 - 0.016" or better yet make sure dwell angle is 59 to 65 deg. Plug distributor vacume line and set your timing to 25deg BTD with timing light

Adjust carburator after timing and dwell angle corrected as needed

76 2002 Sienabraun

2015 BMW F10

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Make sure the spade clip electrical connector to the condenser is tight. Mine was loose and caused a backfire.

Check, it was fine.

 

Adjust your point's gap to 0.014 - 0.016" or better yet make sure dwell angle is 59 to 65 deg. Plug distributor vacume line and set your timing to 25deg BTD with timing light

Adjust carburator after timing and dwell angle corrected as needed

Points were at proper gap. Distributor that is on the car isnt the vaccum advance one. I have  a vaccum one here but alittle leary on taking old one out and re-timing again. And what is the dwell angle? how do you check all that?

 

Sounds like could be running lean, put check jetting on the list.

The car has the 32/36 webber and was a daily driver before being put away for 2 years.

Current - Red 73 2K2 with 318i/Volvo 240 EFI. 5-speed/LSD in soon; 2003 Suzuki V-Strom 1000 Motorcycle

In the past, - Burgandy 76 parts car, scrapped.

                   - Green 75, Sold, being restored now by new owner.

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Check fuel filter, carby bowl and jets for rubbish, fuel quality as its been sitting for a while.

72/2002 Inca

72tii/2002 "Apple"

70/2002 "Five "

73/2002 "Freeda"

2007 Lotus 7 Replica

2011 Ford xr6 Ute

85 E30 325

70 1600-2 "Orange"

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Check fuel filter, carby bowl and jets for rubbish, fuel quality as its been sitting for a while.

Fuel filter is Ok, had the tank out and drained/ cleaned it, then put fresh in. Carb looked good when I had it all out and apart.

Current - Red 73 2K2 with 318i/Volvo 240 EFI. 5-speed/LSD in soon; 2003 Suzuki V-Strom 1000 Motorcycle

In the past, - Burgandy 76 parts car, scrapped.

                   - Green 75, Sold, being restored now by new owner.

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Check all the basics first.  You're on your way, but if this is a new car (to you) checking the valve clearances can't hurt.  Sounds like you're just getting it running, new plugs wires, cap, rotor, points, condenser are a good idea.  Checking the compression is also a good idea.

 

You asked about dwell, which technically is the number of degrees of rotation that the points are closed and supplying power to 'charge' the coil.  Too little dwell time and the coil doesn't charge fully giving a weak spark.  Too much dwell and you may not have enough time between spark events to allow the coil to cool.  The point gap that you set is actually just a shortcut to setting the dwell.  The Bosch factory calculated the dwell time, and then measured the point gap and wrote that into the manuals.  At X degrees of dwell, the gap is typically Y.  So if you set your gap at Y, you're likely going to get a dwell of X.

 

So, if you skipped that last, long-winded paragraph, you should use point gap as a rough get-it-running step or emergency on the side of the road, but you should set the dwell when you're working in your garage and trying to really tune up your engine.

 

Back to your issue, check the idle jet(s) to make sure they're not plugged or obstructed.  Try opening up the idle mixture screw a bit as well.  Also remove the air cleaner and (carefully) look down the carb throat while it's running using a flashlight.  Look for dripping accelerator pump jets.

 

Cleaning and lubing the distributor is also a great idea.  I tend to take the philosophy that if your engine/car has an unknown history, it will pay off huge in the long run if you take the time to go over the basic systems and make sure they're functioning as they should.  That is to say, instead of chasing a single problem and looking for a quick fix to whatever problem is most obvious.  I.E. instead of trying to fix the popping issue, make sure everything is working right and you may just solve problems you didn't even know you had yet.

Edited by Original_Customs

Mark DeBernardi

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Thanks for that, I changed my distributor today, to the vacume advance one, and fixed it! runs like a top now, I'll post a video later. Thanks for all the replys and comments, really helped :)

Current - Red 73 2K2 with 318i/Volvo 240 EFI. 5-speed/LSD in soon; 2003 Suzuki V-Strom 1000 Motorcycle

In the past, - Burgandy 76 parts car, scrapped.

                   - Green 75, Sold, being restored now by new owner.

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