staticattic
Today I was yet again cleaning and adjusting my carbs. This time however, I did something different. Rather than completely taking them off, I tried the "poor man's tune up" as described by John Muir. I revved up the engine, then stuck my hand over the velocity stacks, sealing them off, and let the engine idle down. I noticed something interesting. On 3 & 4, once the engine was idling, if I placed my hand over the velocity stacks, the engine would pop and sputter and start to die. Once I removed my hand, it would come back up. 1 & 2 did something a little different. If I lightly covered 1 & 2's velocity stacks, the idle would change from "bwap bwap bwap bwap" to "rrrrrrrrrrrrrrrrrrr". Then, if I pressed down and formed a seal, it would pop and sputter and start to die. Once I removed my hand, it would come back up. Vacuum leak maybe?

Also, something else I thought of. 3 & 4 were yet again acting up, requiring tinkering with the mixture screws. Could it be possible that the springs on the mixture screws are losing their springiness and letting the mixture screws vibrate around?
Jeff
72 Super Beetle
Quote 0 0
staticattic
UPDATE:

I tried the hand trick on each individual velocity stack after dinking around with the mixture screws. 1, 3, & 4 will all make the engine die if I form a seal. Number 2 will only make the engine pop and sputter, but it doesn't slow down very much. On #2's mixture screw, it seems there is a narrow band where the engine doesn't pop and sputter. It doesn't really fall off and come back no matter if the screw is all the way in or all the way out, it will only make it sputter or not sputter. About 3 to 3.5 turns from the bottom makes it run smooth. When it is running smoothly, that is when the hand trick works.

Jeff
72 Super Beetle
Quote 0 0
staticattic
OK, it is getting late here, 20:00, so I think I am going to have to call it quits until tomorrow. I am sure the neighbors are going to call the cops if I keep revving the engine in my driveway. Here are my results after a drive test:

My top speed appears to be back. I got on the interstate and pushed it to the floor. I got it to 85mph and then got snagged in traffic. She still had more to give though, so I have no doubt she could reach 90mph.

I am running my stinger unbaffled, so the loudness is back.

It pops a little, like if I punch it really quick and let it off while driving. However, if it is idling in my driveway and I blip the throttle bar, it doesn't do it.

It also kind of feels like I am driving up a small hill.

Ultimately, all I really want is a car that will melt faces. I want bystanders looking at me because I am melting their faces, not because it sounds like I am on a duck hunt. It almost feels like I am getting closer, I just need to get all of the tweaks right.

Jeff
72 Super Beetle
Quote 0 0
fatalifeaten
the burbling you're getting under load is typical of an unbaffled stinger.
Daily Driven Dubz Phoenix AZ Family


'66 Deluxe
'63 Deluxe ragtop
'61 Deluxe
Quote 0 0
staticattic
Being a federal employee does have its benefits. I had today off to celebrate Columbus Day, while the wife had to go to work and the kids had to go to school. Since I had the house to myself, I decided the best way to celebrate the life and times of Christopher Columbus would be to go outside and dink with the Bug. The exhaust gasket on cylinder number 2 was gone. It was tight, but no gasket. Not quite sure how that happened, but it is fixed now. I took the entire exhaust system off, replaced all four gaskets, and put new sealant on all of the slip joints. Night and day difference. Even with an unbaffled stinger, I can rev the hell out of it, either driving or sitting in my driveway, and I get nothing but face melting goodness. I do get a little gurgling sound once in awhile while slowing down to stop, but nothing more than what seems to come with the territory when sporting an unbaffled stinger. Now, if my carbs will hold up, looks like I will be melting lots of faces in Tampa Bay.

Speaking of melting faces, I cross paths every now and then with a guy that drives a later model Bug, but it is super loud. Not sure what he is sporting under the hood, but for an exhaust, he just has a straight pipe. It sticks out like a stinger, but instead of making a trumpet like end, it stays the same diameter the entire distance. What kind of pipe is that?

Jeff
72 Super Beetle
Quote 0 0
fatalifeaten
sounds like backyard engineering to me.
Daily Driven Dubz Phoenix AZ Family


'66 Deluxe
'63 Deluxe ragtop
'61 Deluxe
Quote 0 0
bumblebee73
i agree, the smaller outlet will give it a louder and higher pitch sound, i have a reguler tri-mil off road exhaust on my rail and it is louder than a regular megaphone stinger
 
http://s86.photobucket.com/albums/k92/my67truck/my%201641cc%20vw%20rail/

[URL=http://www.mybannermaker.com/link.php?nurl=http%3A%2F%2Fwww.mybannermaker.com][/URL]
Quote 0 0
staticattic

Dude, that is the same exhaust system I want to put on my baja. Can't wait until I actually get to the point of bolting on an exhaust. Just out of curiosity, how do you keep rain out of it? I have been told I can go to a tractor supply house and get a "flapper" to go on top of the pipe. I don't think they will effect performance at all, but what do you think?

Jeff
72 Super Beetle
Quote 0 0
bumblebee73
i keek the rail covered with a good tarp when i'm  not driving it but i also use an old coffie can, as seen in this pic.

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

[URL=http://www.mybannermaker.com/link.php?nurl=http%3A%2F%2Fwww.mybannermaker.com][/URL]
Quote 0 0
fatalifeaten
1 pound coffee can Flappers work fine too. I think TSC has both the clamp on style and the weld on style.
Daily Driven Dubz Phoenix AZ Family


'66 Deluxe
'63 Deluxe ragtop
'61 Deluxe
Quote 0 0
bumblebee73
YUPPERS, works fine for me , and i didn't have to pay any extra for it either. i had a plastic coffie container once, but i wasn't thinking and i put it over the exhaust and melted it , what a mess

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

[URL=http://www.mybannermaker.com/link.php?nurl=http%3A%2F%2Fwww.mybannermaker.com][/URL]
Quote 0 0
olspeed
A tractor rain cap would look kind of funky don't you think...But if you want one go visit your local Caterpillar Dealer as they should have a size that will fit. If you give me the size of the tube (O/D) I have a Cat safe source book that I can use to get you a part number for it. I think a metal coffee can would look more the part though.
Olspeed
66 Ghia, "Dexter" 76 flat window Beetle
It's not a Car it's a VolksWagon!
Quote 0 0
staticattic

I found these jokers: http://store.airflo.com/exhaust-rain-caps.html. I think it might look kind of cool. The best part, I would never have to remember to put it on, as it will always be on. A coffee can, I would probably forget from time to time. Not to mention I would also have to worry about some friendly jackass coming by and taking it off and letting my exhaust fill up with water. I don't think having one of these rain caps on there would effect operation at all. Do you? Of course, I could always go the easy route and drill "drain holes" in my headers. I am sure they will work just as well as the "speed holes" in my fenders.

Jeff
72 Super Beetle
Quote 0 0
olspeed
Air Flow Systems is a good company to deal with, I have used them before and their parts are good quality. But you do have to be careful (even on tractor parts) as there are some vendors out there that sell crap. A company called REGAL Corporation has some pretty shady stuff, rain caps especially. When I mentioned Cat though it's because they should have it on on hand just walk in the door with a measurement for the size you want and walk out, and you will find the price will be close to what Air Flow's is. On the straight stinger you saw it is probably a home made one,but they do look cool though. When I use to AutoX the Ghia I would run a stinger that I made from a oil pressure tube from a D9 Cat transmission(seamless straight tube 3" by 18"but on one end quickly tapers to 2" for an "o"ring) I welded an exhaust flange to it and painted it BBQ black,and off to the races. They always made me put a baffle in though because of noise complaints some even wanted me to switch to a muffler
Olspeed
66 Ghia, "Dexter" 76 flat window Beetle
It's not a Car it's a VolksWagon!
Quote 0 0