Weber Tuniing Question (1 Viewer)

[Boaf 32]

needing the choke pulled out to run smooth certainly indicates too lean. Should have enough adjustment on the mixture screw to go well past the recommended setting to see if you are able to get smooth idle at least on the 45s . The fact you get back firing under constant load higher in rpm range suggests it is not so far off on lower end but gets too lean higher in rev range under load. The 55 idle jets will make it richer overall. But, the fact it was behaving the same way with the previous carb is odd.
some more thoughts:
Float should adjust for full open stop and also for needle valve seated positions. Too low a float setting for seating the needle valve will make the carb run leaner as fuel level gets lower in the main jets. Most needle valve issues in webers seem to be from going rich with no pressure regulator/too high fuel pressure.
is the gas tank venting or do you get vacuum in the tank under load?
Is the cam timing correct (marks aligned when you were reassembling engine)?
do you get full valve lift on all cylinders (no worn lobes)?
compression numbers ok?
condition of pcv valve and check valve on the brake booster? no other vacuum leaks?

Thanks Martin. The carb backfiring with the 38 / 38 has stopped after removing sediment from the filter. Still have a lean problem but running 45's in the idle jet. Need 60's. Working on it.

Boaf

 

[Dizzy]

For the sake of the searchable archive of the post, what were the jets that were supplied in your DGV 32/36? You know, keep someone else from installing trouble.

 

[Dizzy]

Your engine was bored out, and pistons done recently? Valves ground?

 

[Boaf 32]

Your engine was bored out, and pistons done recently? Valves ground?

No Head work. Only cleaned and replaced rubber valve stem seals...

 

[Boaf 32]

Gent's,

Hoping this is the last entry because the future seems good.

Was having trouble setting the timing because the motor would keep cutting out every time I started to see the BB. I ordered two (2) 60 Idle Jets and a Diaphragm for the Accelerator pump. They come today in the mail.

I opened my Idle jets for the Weber 32 / 36 I had purchased. On jet was 45, the other was 60. Thought that was odd but because it was 2 different sizes, thought probably by design.

Pulled the idle jets on my 38 / 38. Both were 45's, I knew that

Now the odd: Tried a test fit of the 60 on one side (outboard) and it fit. Repeated the process on the inside and the 60 wouldn't fit due to smaller thread and holder (exactly like the 32 / 36)

So took a shot, swapped the outboard 45 for a 60 and vundeba'. Set on the timing BB with vacuum removed, adjusted the carb with vacuum removed. Test ride shortly. In a previous post on this thread, I had to keep the manual choke partially closed or I would stall.

Hoping this works! Let you know!

Boaf

 

[Boaf 32]

All,

Good news that the idle and timing is able to be set. I still have a hesitation and struggle for power. Once I get the Jets that were ordered, I'll pull the carb, clean it again, install the new jets.

Boaf

 

[Weber Sarge]

From everything I've read - it sounds like your whole problem is a leak at the adapter plates and that is very common with the Weber adapter kits. The LC kit was one of the worst they designed, no true way to get them down flat enough not to leak at least some with the heating/cooling cycles of the engine. I always flattened those plates or made my own from billet and used much thinner gaskets so the plates don't warp, as well as locktite on the bolts.

Sarge

 

[Boaf 32]

From everything I've read - it sounds like your whole problem is a leak at the adapter plates and that is very common with the Weber adapter kits. The LC kit was one of the worst they designed, no true way to get them down flat enough not to leak at least some with the heating/cooling cycles of the engine. I always flattened those plates or made my own from billet and used much thinner gaskets so the plates don't warp, as well as locktite on the bolts.

Sarge

Thanks Sarge. I did grind down the studds that protruded between 1 and 2 plates. Think that helped. I sprayed starter fluid around and no change in idle speed and new gaskets. I wish I was able to read the main jets when I had the carb out. The vacuum does hold steady.

Will let you know how it goes. Did also use locktite... Great minds think alike.

Boaf

 

[Dizzy]

I would suspect that the intake manifold was cracked where the original exhaust manifold bolts up to it. That is where I would check for a vac leak.

 

[Boaf 32]

Thanks Dizzy. Inspecting it and see no visible cracks. Sprayed it also and found no Idle or open throttle variations. My Jets come in Friday and will install. If the Idle jets were changed by the previous owner, the others probably were as well.

Will have another look at the manifold...

Boaf

 

[Boaf 32]

@Dizzy , @Coolerman @Weber Sarge

Gents,

Carb is off and here is what I have:

Main Jets: (on the bottom of the bowl) are 145
Air Correction Jets: (on the top of the bowl) are 170, is that a strange number?
Idle Jets: Outboard jet (Driver side) 60. Inboard (Passenger side) 45

I also see my bolt that holds the Accelerator Pump Jet (squirt-er) had come loose. Tightened that down and that may have had some fault of the acceleration issue.

Ordered Mains of 155, Air Correction 180. My altitude is only 192 above Sea-Level.

When I get then I will let you know how the install goes.

Boaf

Below From Dizzy, Sarge earlier post:

Main Jets 38/38:
Elevation:
SL (sea level) 1250ft 2500 3750 5000 6250 7500 8725+
F 150 145 140 135 135 130 130 125
2F 155 150 145 140 135 135 130 130


Air Correction 38/38:
Elevation:
SL (sea level) 1250ft 2500 3750 5000 6250 7500 8725+
F 180 180 185 185 190 190 195 200
2F 180 185 185 190 190 195 200 200

Idle jets 38/38:
Elevation:
SL (sea level) 1250ft 2500 3750 5000 6250 7500 8725+
F 60 60 55 55 50 50 45 45
2F 60 60 55 50 50 45 45 40

 

[JohnnyC]

@Boaf 32 "Below From Dizzy"

this should read "Below from JohnnyC" .... just saying since I created it


as said before

155
180
55

is what you should start with

 

[Boaf 32]

@Boaf 32 "Below From Dizzy"

this should read "Below from JohnnyC" .... just saying since I created it


as said before

155
180
55

is what you should start with

I stand corrected, Sorry Johnny C.

Boaf

 

[Dizzy]

My apologies, JohnnyC, I didn't credit you originally, that is how Boaf32 thought it was mine. Anyone have numbers for emulsion tubes, or the pump jet?

 

[JohnnyC]

@Dizzy

if its anything other than F50 on the tubes i'd be suprised

 

[Boaf 32]

Well I am at a loss. I know it is not the carb (which is one good thing from this Whiskey Tango Foxtrot).

60 Idle Jet (One is 45, the other is 60)
155 Main Jets
180 Air Correction Jet

There must be an air leak somewhere. I may replace the manifold gasket again, maybe it was damaged when installed. SOR offers a thicker than stock to eliminate any imperfections. I tried another gasket version that was very thick but too soft, not very durable and did not last.

• It still looses power up a long hill
• It still backfires out of the carb
• going around a corner and hitting the gas, it sometimes will stumble

There are no cracks in the intake manifold. The float in the carb is spot on and the fuel level seems right. I m not sure what else to do. It really isn't safe to drive and nerve racking.

Any thoughts from my LC'rs? @Dizzy , @Coolerman , @Weber Sarge ? Re-install a Fuel Pressure Regulator? Replace the distributor?

Boaf

 

[Dizzy]

Headers?

What are your current settings at for Idle Mix screws and Idle Speed screw?

The image above has a 170 air corrector jet pictured.

 

[Boaf 32]

Yep, that's before I replaced the Jets.

1 1/2 on each idle mix screw, idle speed is at 1/2. Running 750 RPM.

 

[JohnnyC]

Did you bumb the timing to 12-14* as I asked to try ?

 

[Boaf 32]

Did you bumb the timing to 12-14* as I asked to try ?

After installing the new jets, started at the BB to set a baseline. Bumping the timing today and will re-adjust the carb. You think that can help? Re-reading your post now...