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Sun Oct 05, 2014 8:12 am

George here, took the bus out on a drive. With the previous carb settings and ignition the bus seem to accelerate ok, but a little on the sluggest side. Out here in Wisconsin we have hills and some flat areas. I notice while going 50 mph with a light petal I press the petal very little and a noticeable missed on a cylinder or two. Then while holding that petal position the engine caught up to speed to 55mph. I think it's running a little rich so today Sunday, I am going to advance the total advanced to 30 degrees with vacuum off. If this setting cleans it up then I am running rich. My question, do you think I am still on the idle jets or on the mains. This engine is a2007cc 28 vents, 50 idles, 115 mains,200 airs. Thanks, G

Sun Oct 05, 2014 10:15 am

storm wrote: George here, took the bus out on a drive. With the previous carb settings and ignition the bus seem to accelerate ok, but a little on the sluggest side. Out here in Wisconsin we have hills and some flat areas. I notice while going 50 mph with a light petal I press the petal very little and a noticeable missed on a cylinder or two. Then while holding that petal position the engine caught up to speed to 55mph. I think it's running a little rich so today Sunday, I am going to advance the total advanced to 30 degrees with vacuum off. If this setting cleans it up then I am running rich. My question, do you think I am still on the idle jets or on the mains. This engine is a2007cc 28 vents, 50 idles, 115 mains,200 airs. Thanks, G

The richer the mix the less timing you'll want. I'd say you have an ignition issue (electrical).

Sun Oct 05, 2014 12:28 pm

what is your timing at 3500 with the hose on?

Wed Oct 08, 2014 7:37 am

George here, at 3200 rpm no load hose on or hose off timing 35 degrees btdc. Went for another drive 45 miles up and down hills 7to 9 degrees at 50 to 60 mph. Some level road. Heard no ping sound. So the svda is working going up the hills by retarding the spark by the load. I would like to rig up a vacuum gauge in the cab to see this. Took out spark plug a darker tan color. Hav advise John of AC.net so far. He said to contact him if any other problems come up. I bought these carbs from him which he set them up to my particular engine combo. First time using these Weber carbs. So far very happy with the performance on my bus. His service is much appreciated. If you are viewing this post and thinking about putting Webers on your Vw, contact him. G

Wed Oct 08, 2014 1:47 pm

Tuning effects ...

While we are talking about 40mm IDF Webers.

What RPM range is most effected by Velocity Stacks? In general my gut says longer intake tract length moves the torque peak to lower RPM.

Should adding velocity stacks change off-idle drivability? If so, what would you look for?

My feeling after a short drive is that adding the stacks made my slight hesitation on tip in worse and I'm tempted to take a turn out of the accel pump ... or I'm imagining things ...

I need to drive it more ... :-)

Edit:
I adjusted the accel pump leaner 3 turns out (was 2 turns rich before) and it is much crisper.

If I keep gong leaner on the accel pump what should I look for as too lean?

Wed Oct 15, 2014 7:19 am

George here, took bus on a 350 mile tour with other Vw club members. The bus perform well, however when approaching a hill went to apply more petal there was that missed again. My fellow club member said that the pump jet on the acceleration could be a little rich. But after a 100 miles later it did not reacure. Maybe it was clogged with a piece of dirt. Driving was mostly speeds between 45 to 55mph. Fall colors on winding hills on two lane roads. I opened cylinder 1&3 air bypass jets to 1/8 turn. This was to match cylinder 2&4 snail readings. Had to lower idle speed to what I like 750 rpm w/110 cam. Plug color light brown on tip electrode to darker tan inner plug. Looks good to me. Gas mileage 18-20 mpg on a '71 Campmobile. Svda distributor at 3000rpm no load now 37 from 35 degrees btdc hose on or off. Head temp 285 oil 185

Wed Oct 15, 2014 8:14 pm

storm wrote: George here, took bus on a 350 mile tour with other Vw club members. The bus perform well, however when approaching a hill went to apply more petal there was that missed again. My fellow club member said that the pump jet on the acceleration could be a little rich. But after a 100 miles later it did not reacure. Maybe it was clogged with a piece of dirt. Driving was mostly speeds between 45 to 55mph. Fall colors on winding hills on two lane roads. I opened cylinder 1&3 air bypass jets to 1/8 turn. This was to match cylinder 2&4 snail readings. Had to lower idle speed to what I like 750 rpm w/110 cam. Plug color light brown on tip electrode to darker tan inner plug. Looks good to me. Gas mileage 18-20 mpg on a '71 Campmobile. Svda distributor at 3000rpm no load now 37 from 35 degrees btdc hose on or off. Head temp 285 oil 185

The air by-pass screws on the IDFs are used to balance air flow between the barrels of each carb itself. Not from one side to the other.

Total timing with the SVDA should be 28-30 degrees BTDC full with hose off at ~3200+rpm's.

Thu Oct 16, 2014 7:10 am

George here, I have all barrels in the carbs pulling the same on the snail gauge 5. #2&4 carbs air bypass screws are closed. I bought these carbs from Air Cooled.net. They set them up to my engine combo. In my opinion they did a very good job. John, the tuning expert has advise me to adjust the ignition timing and carb settings. I respect that. I have older Vw bugs that relie on vacuum ignition only for spark advance. 28-30 advance are for .009 distributers. You should read John's technical articles about this subject. Thanks anyway for your input.. G.

Thu Oct 16, 2014 1:57 pm

storm wrote: George here, I have all barrels in the carbs pulling the same on the snail gauge 5. #2&4 carbs air bypass screws are closed. I bought these carbs from Air Cooled.net. They set them up to my engine combo. In my opinion they did a very good job. John, the tuning expert has advise me to adjust the ignition timing and carb settings. I respect that. I have older Vw bugs that relie on vacuum ignition only for spark advance. 28-30 advance are for .009 distributers. You should read John's technical articles about this subject. Thanks anyway for your input.. G.

I'm aware of John.

009 distributors are NOT the only timed at 28-30 degrees hose off (actually more like 28-32 degrees BTDC). The SVDA is timed no different than a 009...just ensure the hose is off.

What is your altitude? That would likely be the only time you'd time beyond 32 degrees BTDC at ~ 3200rpms.

But if your not at any height your asking for trouble with 35+ degrees full advance timing...think hole in piston = BOOM!