Exhaust loud popping: Lean? Rich? Fuel? What else?

[TEM666666]

no worries - can also be around mid to late afternoon Monday - I golf in Newmarket at 10:30

Tee off at 10:30? I still have a day job!

I got good news though! I fixed it! (I think?). Thanks everyone for your suggestions and JP who even offered to come lend me a hand!

Got up this morning, ate breakfast, and started wrenching. I totally forgot about my original plan and went with my gut. (assuming it's all mechanical linkages issues. Otherwise I'm back to anger, denial, then internet confusion stages in problem solving if it's something else like a vacuum issue, etc).

-Took out the dashpot covers, piston/needle.
-loosened the choke linkage nuts (item 5 on my diagram) for both chokes.
-backed out high speed idle screws
-dialed both mixture nuts to T=0 (flush at the top).
-dialed in 13 flats down on both, measured approx 0.116 and 0.118" down.
-snug tight the choke linkage nuts.
-pulled choke slowly inside car watching the chokes go down via gap hood opening gap (this is where JPSmit would come in handy!)
-one side went 1/4" down before other one moved!
-loosen the left one (slow one) and hand held the spring down to tighten up the slack a bit), tightened the linkage nut.
-pulled choke... both seems to move almost together now.
-recheck jet recessed distance (same as before exercising choke).
-put the piston/needle and dashpot covers back on.

-Stated the car and let it warm up.
-loosened the throttle linkages. This is interesting. My right idle screw that wasn't touching the stops, the throttle was held hostage by the left one originally since the previous setting was way off. So when the linkages were disconnected; it went "click" and it rpm dropped! So I went and shut off the engine to get things closer before starting again.
-The original throttle stop was actually held down by the butterflys! This is like a good way to wear out a carb?
-I'm assuming the throttle linkage stop is the pointy wedge pointing towards you that rests pressing upwards on the choke linkage. I had like a 1/2" gap there which is now gone (released the linkages screws and it went CLICK...).
-Dialed in about 2 turns down from flush on the idle screws.
-Start the engine.
-sync idle with rubber hose hiss method. Adjusted from just under 2000 down to 1100.
-shut car off.
-set the gap for throttle linkage on both sides (item 3 on diagram) and tighten down.
-Start car, recheck and adjust mixture, idle rpm, back and forth a few times till its (seems) right.
-pull choke, set high speed idle. Now when I pulled the choke and went to look at the carb, I can visually see one piston like 1/8" higher than the other. I turned the idle screws until they visually look about the same height and listed for hiss again. The rpm was around 3000 (which I thought was highish?), but choke operates up/down fine, I'm not going to keep fighting it.
put the air filters back on... went for a nice drive. Temperature didn't get as high as it did the bad popping day but the engine ran smoother than usual and no popping noise. I will check the plugs sometime (I don't like removing/installing hot plugs). Other than that, I think I seem to have fixed it...

 

[JPSmit]

sounds great! glad it worked out - being methodical - with time is terrific! And FWIW I do have a day job :grin: but I get to make my own hours (and the ones I don't get to choose are often evenings and weekends)

look forward to connecting regardless.

cheers!

 

[Joe Schlosser]

Congratulations.
The idle speed choked is way too high. There is a screw to adjust the throttle opening on both carbs that operates off a cam on the choke linkage. 2000 is a nice place.
Everything should be set (carbs synched) at regular idle with the choke in. You are not going to drive the car much with the choke out.
With everything set both carb pistons should raise up almost the same as the RPMs increase.

 

[TEM666666]

Thank you gentlemen for the support!

JP, I think we will definitely meet up in the near future!

Back to the choke on and fast idle.
How much should the jets lower with full choke open?
How much should the choke knob come out from the dash? Mine comes out pretty far. As I push in the rpm drops; and perhaps I can just moderate it to around 2k on warming up?
The choke knob is very tight (was tight on my old mini too).. should it be smooth/easy? grease the cable?

 

[JPSmit]

Can't tell you about your first two question, but, in terms of choke cable - I don't really think it matters except to say that you can shorten it at the other end. Mine comes out probably 1 1/2 - 2 inches.

If I am telling you the obvious, I apologize but, mine pulls out and then I "cinch" it by turning it to the right - so, have you turned it to the left to see if it turns more smoothly?

 

[TEM666666]

It's already fully turned to the left. It's extremely tight to pull. Maybe when I get around to it, I will try greasing up the cable. I guess I can either pull it partially or install a limiting collar on the cable at the carb end.