73 Super Beetle, Solex carburetor adjustment

[glennj3cub]

I’ve been working on this Bug for a while now and I drive it once a week now for just a little bit.
So I’ve done what I believe is a good tune up after she sat for years. Post carburetor rebuilt by me, valves checked & adjusted, timing set ( but not too sure it is set right).
Choke set correctly. I got her cranking up initially very well. Driving through the gears it skips about midway through 2nd & 3 rd then steadies out and excellerates well.
At idle & while adjusting the carburetor, it sounds like I have it right. It got dark so I used a flashlight & I could see the exhaust as well as smell that nasty smell behind the car. Inside of the exhaust pipes are black.
Note that while cold it cranks up easy but aster running & I switch it off it will only crank up again by holding the pedal to the floor while turning it over. Then it starts firing I have to keep it on the floor until it is running (begins like it’s running on 3 cylinders then smoothes out).
I began with both screws at 2 1/2 turns out. I got the idle speed up then adjusted the small screw.
A little frustrating at this point but I’d love some help.
Thanks ahead of time.

[Cusser]

Is your epoxy patch over the rear hole holding up?

I run a 30/31PICT on a DP manifold with an adapter, on my 1600cc engine, runs fine.
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[glennj3cub]

I saw that on there. I don’t know what it is or why it’s there. Does that answer your question?
Thanks

[VW_Jimbo]

Lots of questions first....

When was the last tune up?

What do the points look like? Or is it electronic ignition now?

How old is the coil and have you tested the spark from it?

What do the cap and rotor look like?

Looks like you have an 009 distributor, but just in case you have it disconnected, does the advance can work and is the points plate action smooth as butter?

How old is the condenser, if still there?

Then, last valve adjustment? Anything odd?

Last compression test?

Clean fuel system? Filter installed?

That should get it going in the right direction!

FYI The epoxy smear over the casting plug hole is to keep the metal plug in place. On many Bugs, a backfire up through the carb, would send this plug off into the abyss known as the engine compartment. Rebuilders started smearing epoxy over the hole back in the mid 80s. It worked and did a great job! But you still have to check for a vacuum leak there! Thus the question asked.
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[glennj3cub]

Thanks, I sprayed carb cleaner all around it and showed no sign if a vacuum leak.
Valves checked & adjusted last week. New plugs, wires & electronic ignition. Removed engine & replaced the rubber seals.
New gas tank & lines, new fuel pump & filters. New coil.
I run regular gas.
I checked today & the small screw is turned out about 1 1/4 turn. The idle speed is good.
Like I said, it cranks up easy the first time but I have to hold the pedal to the floor & hold the ignition until it’s running, but it’s sputtering for a little, then smoothed out.
The exhaust pipes are black.

[ashman40]

[glennj3cub]

Excellent advice. I may have a pressure regulator (I don’t have anything to actually measure it).
Would too much pressure cause it to run rich? I guess it would🤨😜!

[VW_Jimbo]

[glennj3cub]

I put the pressure regulator on at 2 lbs. it now cranks up the 2nd time after running!it still sputters a little at higher RPM. Maybe it needs new plugs after running rich??
Thanks

[FreeBug]

just a tought: put back the points and see how it goes.

[VW_Jimbo]

[glennj3cub]

Yes I thought that should be lean too.
It’s never had points (since I’ve had it).

[glennj3cub]

I got a tachometer in today. It’s idling at 1000. So now I can do a better job of setting the carburetor. It drops a beat often so it’s not steady regular. I pulled 2 plugs (they are virtually new) they were dark like (rich) so I brushed them clean. Need to do the other 2.
What name brand plugs do you like best?

[ashman40]

Run the engine for a while to get it warmed up then rev it and hold at high rpms for a bit to force the fuel pump to put out max pressure/volume.
Shut the engine off without letting it idle.
Remove the top of the carb (5 screws) being careful not to rip the gasket.
Check the fuel level in the bowl. If the float and inlet valve were doing their job the level should be 3/4" from the top. Any higher in the bowl and fuel could start to flow out the venturi and down the carb as raw fuel. This would flood the engine and make it run rich.
If needed, add gaskets between the inlet valve and the top cover to make the valve close earlier (lower the fuel level). You do not want it higher than 3/4" and not much lower as this could starve the engine of fuel at higher rpms.
Too much fuel pressure results in the same thing with the inlet valve being unable to stop the fuel flow.
_________________
AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[VW_Jimbo]

[glennj3cub]

Thanks Ashman, I put a pressure regulator on last week, that seems to have fixed the rich problem!
I’ll put it at 850 to 900 rpm!

[vamram]

[glennj3cub]

It’s an MR Gasket regulator. Set at 2.
I’ve been trying to set the carburetor & I checked the timing. The distributor was loose & had slipped some. I think it’s correct now. I’ll post a video of it if I can.
Also it is not steady like it hits a skip.
After turning it off it won’t crank up. I looked inside the carburetor throat & it’s steady pumping gas into the throat (engine off).
I’m now removing the upper portion of the carb to look at it.

[glennj3cub]

The float chamber has fuel in it but is low. I poured some gas into the float chamber. The float floats but fuel is pumping into the throat until the float chamber is low!
Weird!

[ashman40]