staticattic

I hate to keep beating a dead horse about stinger exhausts, but I have another question. A couple of days ago, I got a letter from my home owners association saying I needed to power wash my driveway due to all of the "black circles". The circles that they are referring to are not oil. Surprisingly, my car drips very little. What they are referring to are the carbon circles that come from my exhaust. Quite a while back, I swapped my stinger out for a hideout muffler. I did this not because of my neighbors complaining of the noise, but rather I was tired of hearing the "popping" noise every time I let off the gas. I called around to several places and always got the same story, "A stinger has no back pressure. The popping comes from negative back pressure causing air to flow backwards through your engine. That causes detonation of any unburned fuel in your exhaust stroke." That sounded like a logical explanation to me. So I bought a hide out muffler and that opened a new problem. The exhaust blows straight down and creates black circles everywhere. And, my car still "pops", only it is much quieter. I would love to put my stinger back on, but that popping gets on my nerves. I have been looking at dual quiet packs since they blow straight backwards. However, if that is what I need to fix the problem, so be it. But it just seems to me something is not right somewhere. I have dropped it off several times at the shop and had my carbs adjusted and timing checked. I don't want to keep spending money doing that. Would an exhaust leak cause the "popping" problem? Other than that, everything is running great. 

Jeff
72 Super Beetle
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bumblebee73


check your valve adjustment , i keep mine at around .006. a valve that is adjusted to tight could cause a leak around the valve seat. also valves to tight can end up causing a burnt valve(which won't seat correctly), which will cause a popping out the exhaust. check your plugs , i run bosch in my 1641 duelcarb engine and there set at .035. .and double check for vacume leaks, i use gumcutter(carb cleaner)with the car running, spray all of your intake(s) when the carb cleaner gets sucked it by a vacume leak the idle will change .
http://s86.photobucket.com/albums/k92/my67truck/my%201641cc%20vw%20rail/

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staticattic
Check this out. Maybe someone can explain this to me. I bought some carb cleaner and sprayed it around my manifolds and intakes and got nothing. The idle did not change at all. Since I had it, I figured I might as well shoot some in my carbs since I had never cleaned them before. The back of the bottle said to do it "routinely" although I don't know how often "routinely" is. I am guessing every oil change? Anyway, I also put my stinger back on. Since it is summer and all the Harley's are out and about, I might as well join in the fun and sport a loud engine too. Plus I really like the looks of the stinger. After I blasted my carbs with the cleaner and increased my RPM's for 30 seconds per the instructions, I noticed she was starting easier. Not only that, but the stinger has almost stopped popping. It is not entirely pop free, but the pops happen few and far between. The best part, whenever the stinger is on, she accelerates much faster than when she has the hide out muffler. Not really any changes in top speed, but she can really get up and go. To me, that is more important anyway. With that. I am guessing the source of my problem then, would be that my carbs just needed cleaning. Is that a logical assumption?
Jeff
72 Super Beetle
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bumblebee73

ALSO YOU RUN DUEL CARBS , DO YOU RUN IT EASY ,LIKE PUTTING AROUND NICE AND EASY NOT WINEING IT OUT. IF SO , YOUR PLUGS, VALVES AND PISTON TOPS WILL BUILD UP WITH CARBON. MY NEW 1641 WITH DUEL SOLEX'S, WHEN I BOUGHT IT TAY (THE GUY WHO BUILT IT AND MANY OTHER RACE ENGINES) TOLD ME NOT TO BE AFRAID AND RUN IT HARD ,NOT ALL THE TIME , BUT FROM TIME TO TIME TO GET INTO IT AND WINE IT OUT, THAT HELPS KEEP THE CARBON BLOWN AND BURNED OFF, YOU HAVE TO THINK ABOUT IT , THERE IS ALOT OF GAS GETTING PUMPED IN TO THE ENGINE . 

http://s86.photobucket.com/albums/k92/my67truck/my%201641cc%20vw%20rail/

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staticattic

It is interesting you brought that up. Knowing what I know now, if I could go back in time and make different decisions for my engine, I think I would change some things. My engine works great when I can really stomp on it and wind it out. When ever I accelerate really hard to the speed limit, oh my god, she runs like a dream. The problem being, I do have to endure lots of stop and go traffic. My drive to work is 32 miles one way. With all of the construction that seems to never end, all but about 7 miles of it is stop and go. In that stop and go, I rarely get fast enough to even take it out of second gear. I think my foot is on my brake pedal more often than my gas pedal. After paying the pros several times to adjust my carbs and valves, checking for vacuum leaks, and finally blasting my carbs with cleaner, I had pretty much drawn the conclusion that you discussed. I guess I need to leave earlier for work. If I leave every morning at 0530, I should miss most of the traffic. That way, every morning at least, I could really wind it out and give it a good work out. I figured I would do that every day for a week and see what happens.

Jeff
72 Super Beetle
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MLTigger
I'd hate to live in a neighborhood that would complain about little black circles on my driveway.  Tell these complainers to get a real life.  That's why I like living out in the country.

Now for a quick question.
Does anyone know if you wind out your stock 1600 DP with a stock carb is it possible to overrev the engine? Or if you floor it in fourth will it just stop accelerating. 
I remember in my '69 1500 SP I drove the California highways with the pedal to the metal with no adverse effects.
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Jerky_san

if i remember right the stock carb will allow an over rev.. its not by far but your starting to push it..

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Ryan

As long as you're in fourth gear, there's no risk of over-revving unless you're going down a pretty good hill.  --Ryan

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beetledon

Hope you solved your black circle problem. Maybe you could move and own a place with a gravel driveway. I had the same problem with my headers and hideout under the fender muffler. I bought a 45 degree elbow from Auto Zone, cut the down pointing exaust pipe a little shorter and clamped the elbow on and painted it black with heat resistant paint.

beetledon
72 blue super
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