9 replies to this topic

[claysummers]

Been running this carb on the tired 186 in my ute.
Still stumbling slightly off idle when warmed up. I gave it a good clean and blow out and put a kit through it. Accelerator pump set in middle hole and atomising, bit weak maybe. I have hot coolant flow through manifold. I had to insert some tube in what I assumed to be the vacuum advance port. I’m not sure if this is correct. Blipping throttle gives a lot of advance if I recall correctly.

It was suggested that some bypass passages may be blocked and would benefit from sonic cleaning.

These were factory fitted to 75 base 173 manual LH LX according to documentation. Anyone familiar with these and can comment on the vacuum port please?
Cheers
Clay


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[LJ RB30]

Accelerator pump needs to be an instantaneous strong squirt So if you have kitted it and still is weak make sure the check valve is sealing. Don’t know bout vacuum port sorry

Edited by LJ RB30, 24 April 2021 - 03:19 PM.

[yel327]

I think it should have two vacuum ports if it is from a 1975 car. One will be for the dizzy on a manual and the canister operation. The other for the dizzy on an auto. If you use the ported vacuum designed for a manual on an auto car it won’t idle properly as the auto car wants vacuum advance at idle to compensate for the converter. Not sure if this is related to your problem but I have seen a similar problem with a manual carby on an auto engine.

Edited by yel327, 24 April 2021 - 06:46 PM.

[claysummers]

Thanks Trevor and Byron. Manual specific carb this one so I think vacuum is right. I will investigate check valve as I reckon the squirt is a bit weak.


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[yel327]

There should be no manual specific carb though once canisters are fitted which started on 1/1/75.

[claysummers]

23 3081 was 173 LJ LH auto according to my info. Bendix Stromberg documentation differentiates manual and auto carbs through HX - UC.


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[yel327]

Interesting. Will have a look. In Quadrajets once canisters are fitted there are no more auto or manual carbs, they are the same. I assumed Strombergs were similar but maybe not. If it’s from a canister car it should have a pipe connection for the canister venting of the fuel bowl.

[claysummers]

Has a canister port. I put coarse steel wool in it so it vents to atmosphere.

I will be putting a WW on some time soon but will probably use this to first fire and bed lifters in. Will depend how much time I have to get it set up before I head off to the FB EK nats in Toowoomba early June. 5000km round trip via sunny coast and Sydney back to Willunga.


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[warrenm]

Does the motor have std factory camshaft? If it doesn't, you may need to open up the accelerator discharge jet.

[claysummers]

Factory cam was in it Warren. Going to a Dynotec CM205D. 0.429”/0.429”, 214/[email protected]”.


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