Sticky second throat in 4M carby

[haison]

Yet another questions about my carburetted bastard child..
Seems the second throat doesn't want to open, the vacuum diaphragm is fine and when i manually pull on it it will open, but some reason theres not enough vacuum to pull it open on it's own.
I know you can play with timing to get more vacuum through it but i really can't be stuffed right now.
I've tried lubing the shaft (heheheh) and working it in but it didn't make a difference.
Any other tricks to get it to open or am i gunna have to get my hands dirty again?

Knowing the carby wasn't completely openening made me feel a lot as the car right now feels absolutely gutless .

Thanks again!

[Screamn_Sleeka]

Was the engine at operating temperature when you were doing this?

[allencr]

"I know you can play with timing to get more vacuum through it"

I don't know that!!!
If you've put a 'tell tale' on it, like a little piece of wire or a twist-tie, to know that it actually isn't working when being driven, then you've got a problem, but if you're just sitting there reving it up, you're not going to see much from most of the vac. operated ones.

[haison]

Sleeka - Yep at operating temp.

allencr - Yeah i didn't know that till i got told yesterday. Apparently it's a full days job to get it sorted.
I can tell it's not working when driven cause it gets to about 5k rpm and really struggles to breathe. I can tell from the sound of the exhaust too.

[allencr]

allencr - Yeah i didn't know that till i got told yesterday.

That was sarcasm. I don't know it, because it isn't true!
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If it hadn't been operating, it probably would have been gummed/carboned up and would have required some force to break loose & then worked at least a few times to get it moving freely. It has moved freely since you first looked at it, hasn't it?

What's the compression?

[IN 05 NT]

have you replaced the vaccum line? no splits in the line?

a shit load of carby cleaner, and a few hard revs have soreted out a few sticky 2nd throats on customers cars.....

if your not expexting the throat to open, when it does the noise will make you jump.......

i jumped 3 feet when working on a mates wb caprice when the 2nd throat finally opened, the roar shocked me

[haison]

Yeah scared the crap outta myself when i manually opened it, nice sound but .
There isn't a vacuum line to the diaphragm.. it's internally regulated. i.e the vacuum is drawn thru a groove in the alloy cover from.. somewhere. But basically no hoses that i can see in relation to that bit.

No it hasn't started opening since playing with it. I don't think it's all that gummed up, it seems to open with out much of a hassle. Just doesn't seem to be enough vacuum to do it on it's own.

The carby didn't seem to have much in the way of carbon build up or anything and was already pulled apart and cleaned.

[cambelt]

did he charge u for this carby setup and or 4M or was it free . hehe
dave

[haison]

lol sif i'd pay for it, i'm asian