Poor running 1641 TP

[roscopeco10]

Mayday pulling my hair out with this one! On my 3rd exchanged 34 pict Bocar carb. Fist had an air in leak issues so wasnt ticking over once choke had dropped out.
carb no.1 & no.2 had only done 50 odd miles before playing up and straight replacement ran fine each time but not for long. Lost count how many times I have done valve clearances, dizzy timing and usual 2 and half turns out procedure on each carb set up. Now I am on carb no.3, It runs ok with choke then pretty lumpy with big flat spots until it warms up some more and evens out but still only just ticks over. To get it ticking over only just, the carb screws are out like 4/5 turns!
Wondering if the stock fuel pump is not providing enough fuel ??

Its a recon block under 1k miles, 1641 TP new heads, pots, pistons, "CARB!" fuel pump & filter, pretty much newish everything

Would love any ideas
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73 Dormobile now a 73 crew cab & 79 crew cab, ping me anything crew cab related!

[Starbucket]

Feel the heat riser under the manifold, it should be too hot to touch after 3-5 min.s running, if OK look down the carb (motor off) and open the throttle slowly, the accelerator pump should start squirting gas as soon as you open the throttle and continue until WOT, if not adjust the cam screw toward +.

[roscopeco10]

Will check riser in the morning and check carb. I am guessing I am looking for fuel being squirted from what is in the float chamber
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73 Dormobile now a 73 crew cab & 79 crew cab, ping me anything crew cab related!

[Starbucket]

[busdaddy]

Please tell us about the condition of your fuel tank and what the last fuel filter looked like inside. Also tell us what distributor you have and how you are timing it.
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[OB Bus]

[SGKent]

I'd also check the manifold boots for leaks and cracks, as well as the brake booster to be sure it is not leaking.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[wcfvw69]

Post some pictures of your engine and engine compartment. As others have stated, most aftermarket carbs are better used as door stops.

Volkzbitz.com sells beautifully restored German Solex 34-3 carbs. I run restored German, Solex carbs, Pierburg fuel pumps and Bosch distributor.

These were high quality parts that are easily restored back to like new condition.
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[aeromech]

A Volkzbitz Solex 34pict-3 is about $250 outright. Best money you could spend. As others have said, there are many other things to consider such as manifold heat and what distributor you’re using. Vacuum leaks, contaminated fuel, etc. all need to be considered. Best thing you could do right now is post 4-5 pictures of your engine.
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[roscopeco10]

Thank you for the tips so far, pics will be posted later today after I get chance to try some of the suggestions out.
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73 Dormobile now a 73 crew cab & 79 crew cab, ping me anything crew cab related!

[Spike0180]

What cam is in it?
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[scrivyscriv]

In my short time around the block with aftermarket carburetors.. I have found they need to be opened up and cleaned, and you need to set the float height. Pull all four jets out and blow them and their passages out with shop air.

The number of turns out on the idle mixture is not really as important as how rich or lean the mixture actually is, but you won't know that info without an air fuel ratio gauge.

There is a good possibility the throttle shaft is too loose in its bores and is leaning out the mixture.. you can't adjust a throttle shaft vacuum leak out, but you can hide it by running too rich at idle. Yes new carburetors can have too much clearance at the throttle shaft bores.. it's not from wear, it's from bad machining tolerances during manufacture.
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[TomWesty]

[deezal]

To much fuel pressure maybe?

[roscopeco10]

So cant see any juice squirting in the carb with engine off when I pull throttle lever and pre heaters vary in temp after 5 mins definately not hot under the carb mount.

https://youtu.be/uGJyzrDbvms

Delayed sorting this issue, down to the Accelerator pedal hinge snapping yesterday !! woohoo
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73 Dormobile now a 73 crew cab & 79 crew cab, ping me anything crew cab related!

[busdaddy]

That's quite the combination of aftermarket new stuff, a little flaw here and a bit of underperformance there all adds up to a less than optimal engine.

At first glance I see:
Aircleaner
Carb
Distributor
Possible small lower pulley
Long belt (slow fan)
No crankcase breather
No wire on oil pressure switch

Some needs immediate attention, others can be replaced one at a time for a gradual improvement in performance.
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Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
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[Starbucket]

[SGKent]

or the muffler wasn't drilled out for preheat. Some come with a welded plug and have to be drilled to allow the pre-heat to work.
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[OB Bus]

[aeromech]

On a positive note, it’s clean.

You know, a new guy walks into a VW parts house and he sees all this crap for sale. He doesn’t know better and relies on the parts guy to steer him in the right direction. That’s where the error lies
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Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound