Amal 932 O-ring seal between carb & manifold....thick or thin? (stock 1973 Interstate)

Greetings all,
I did check Forum threads for tech info on this topic but lucked out.

When I researched carb rebuild components online a shop listed manifold O-ring seals. (not at the phenolic insulators) They offered two thick O-rings part no. 70-9711 and two thin ones part no. 622-101, as replacement options for my carb to manifold connections.

I measured the cross section of my O-rings currently installed at about .057" thick across the sealing surfaces and about .065" at the ID to OD cross section. (probably less due to years of compressed bolt up) Both choices are described as "Amal High Temp Carb Mounting O-Rings".

I'm hesitant to use the thicker one since it may not be correct for my carb set up and could lead to warping the 2-bolt flange by the ape that buys my machine when I croak!

Thanks in advance for your help.
Dave

The thicker one is probably the one Triumph used as a way to add a block to heat propagation. But there are other parts involved so stick with the normal Amal specified one.

Interstate said:

They offered two thick O-rings part no. 70-9711

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They are for Triumph twins that are supposed to have a gap between the manifold and the carb.

OK....just getting back online, and thanks! The sources I used to look up the seals did seem to imply the thicker O-ring was intended for a Triumph. The parts listings weren't clear to me. The Amal O-ring groove is quite narrow for anything larger.

FYI during parts search I've ordered the silicon valve cover gaskets from JS Motorsports in CA...hope they workout.
Thanks again,
Dave

O-rings.. never used them, never missed them.

ludwig said:

O-rings.. never used them, never missed them.

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So what's your preference Ludwig? the solid phenol spacer or ????

Ive used just a phenolic at carb to mani flange, but with a sealant (permatex ultra grey) both sides of phenolic as they do not seal air tight otherwise. Used the insulator to help with carb over heating, esp when I was running single carb...the big block of alloy 2 into 1 mani did not shed heat as well as two manis. Since gone back to the oring setup and two cabs as Norton gods intended.