Aircooled.net SVDA

[DjEep]

Got it today and put it on tonite, but I missed the closing bell at the FLAPS so I couldn't get the proper vac hose. Got it running fine sans vac, the guy at the factory even set the points right .

I was fiddling with the vac port that I believe is the proper one, on the left side of the 34/3, when I noticed that I was engulfed in smoke. Apparently a vac leak at that port causes quite a rich burn, even a few minutes after it is corrected.

Anywae, I can't wait to test it out on a daytrip up the coast tomorrow

Stupid ACN backordered my new dizzy clamp, of all things though...

[DurocShark]

Stupid ACN backordered my new dizzy clamp, of all things though...

It's not like your old one wore out... Though it is nice to have the spare dizzy set and timed and ready to just drop in.

[DjEep]

'zactly

[DjEep]

Took her for a test drive yesterday and she ate up the hills in town. But once I got her out on the highway she seemed to feel a little more sluggish in 4th gear, even third on the bigger hills. I tried to crest a small hill in 4th and was treated to some definite pinging.

Pulled off in the town where I bought my other bus to see if the PO had a timing light, and after an hour of searching, checked the timing. Spot on according to the instructions. 30 btdc no vac, 40 btdc w/ vac. @ 3500 rpm.

Feels like it wants to ping anywhere over half throttle in fourth and third.

I am going to fudge with the timing later, see if I can back it off a bit without sacrificing too much power. But I am worried my carb is pulling too much vacuum. Any suggestions?

[vdubyah73]

Is the vacuum sourcr from your carb pulling vacuum at idle? Should be no vac at idle. Vacuum advance port is usually about even with the throttle plate, not in the base of the carb.

Bill

[chitwnvw]

Is there an advantage to running the vac from both carbs? (on a dual carb setup, obviously...)

[vdubyah73]

Is there an advantage to running the vac from both carbs? (on a dual carb setup, obviously...)

I take vac from both carbs on my bus with 34 ICT's and on my buggy with 44 IDF's.On the IDF's there is only vac from 1 barrel on each carb. Don't know if it's an advantage on a dual single barrel but it's required for a smooth vac signal on dual 2 barrel setups.

Bill

[DjEep]

Is the vacuum sourcr from your carb pulling vacuum at idle? Should be no vac at idle. Vacuum advance port is usually about even with the throttle plate, not in the base of the carb.

Bill

It's gotta be the correctt port, the one on the left, right on top of the idle screw. Not the one at the base or the one sticking straight out the rear. It has no vac at idle, but it jumps right up at the slightest throttle.

The instructions for the SVDA says no vac @ idle, vac until 1/3 - 1/2 throttle, then back down to no vac at full throttle.

When testing, i couldn't get much past half throttle, since with no load it would rev way up. Do I just blip the throttle all the way super quick and see if it jumps then dives?

W/ the timing light it jumps right up from about 6-7* btc to about 25-30* by about 2000rpm.

[Randy in Maine]

Does it jump up there with the vacuum connected?

If I recall corectly, you set it up to wind in the centrifical advance and then check it with the vacuum advance hooked up to make sure you are not getting too much total advance when you are wound up at partial throttle, like driving down the road at 60 with about 1/3 of the throttle in and 2/3s left.

[vdubyah73]

Look for vac leaks. Manifolds to heads, rubber joints for unseen cracks on the bottom, carb to manifold joint etc... Try a valve adjust and retune the carb idle mixture, speed and timing. When you retune the carb and timing you are kinda like a dog chasing its tail. Every adjustment made changes the others. change the mixture you have to change idle speed, change the idle speed you have to check the timing. You want to make sure that the throttle plate is where it belongs for idle, so that you are not idleing on the progression circuit. Idling on the progression circuit will send vac to the distributor while idling.

You may have to rejet with the better spark curve. What I'm saying is that the flat spot with the 009 could have been a lean condition that showed itself with a big bog. Now with the advance curve that is correct the lean condition is showing up in a different way. The odd combo described in the og post may never have run correctly either, and showed itself as a big bog with the 009 and is now a borderline ping.

Good luck keep fiddling you'll get it.

Bill

[DjEep]

Well I brought down the idle speed and the timing, Now a nice 850 and TDC. Seems to be doing a lot better now. Took it for a test drive, including some abuse up a 55mph hill and it seems to have reclaimed the lost top end and got rid of the ping. Barely less oomph off the line, but more than with the 009 anyday. She even sounds better now. More bass and nice low, even idle.

M'lady takes it to work during the week, so I'll see what happens when I drive it next.

[vdubyah73]

There ya go Keep fiddling you'll find the sweet spot in time. The full in timing with vac connected should be checked from time to time for a couple 1000 miles as the vac diaphram breaks in and gives more movement.

Bill

[DjEep]

I also noticed today that she runs a whole lot smoother all around now (the bus, not my girlfriend). Idle sounds nicer, and not only does she accelerate smoother, engine vibration is waaaay down.

Also, she is less speedy on the freeway, which is a good thing. Used to want to drift up to 70 to find the sweet spot, which probably wasn't too great for the headtemps. Now she feels better around 60, with power to spare if necessary.