engine and drivetrain Popping From Exhaust

[rickm]

I've had the 67 out for some fall drives and have noticed occasional popping coming from the exhaust. At first I thought it was some regular gas I put in by mistake, but it continues to pop and miss a bit. Not major, but annoying. It occurs more at low speeds than, say, above 60 or so. Do the Mikunis need adjusting? Any thoughts? What else could it be? Thanks.

[adawil2002]

Carb adjustment

Check timing

Are you running points? Replace or clean them. If running Pertronix you're fine.

Check, clean or replace distributor cap.

Check, clean or replace rotor.

Check, plug wires, replace if you can't remember when they were replaced.

 

Check distributor for metal shavings around the shaft. If so buy an I.E. distributor or send yours to Advanced Distributors to be rebuilt and recurved.

Edited October 16, 2013 by adawil2002

[tim385]

Possibly running lean, maybe an air leak.

[Emyers]

When exactly does it pop/backfire thru the exhaust?  If it does this when you are slowing, foot off the gas and car in gear, you probably need to look at the idle jets, as it sounds like you are a bit lean.  How far are the idle mixture screws turned out for a best idle. If more than two turns from closed you need to increase the size of the idle jets.  Went thru this exercise with the Mikuni 44s on my car.

Earl

74 02Lux

02 M Roadster

72 Volvo 1800ES