Best jets for 1971 Beetle 1300 Twin port

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73type2
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Best jets for 1971 Beetle 1300 Twin port

Post by 73type2 » Thu May 17, 2018 11:16 am

What is the best sizes of main and air corrector jets to be used on a 1971 Beetle 1300 twin port at the coast?



Dawie
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Re: Best jets for 1971 Beetle 1300 Twin port

Post by Dawie » Thu May 17, 2018 12:20 pm

When dual port 1300 was introduced late 1970 (for the 1971 production year), it had unusually big jets, but this was found to be a problem, so VW changed to smaller jetting during the first year.
With it's original German 31PICT carb with 25.5mm venturi, they used 130 mains and 110 air correction.
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Re: Best jets for 1971 Beetle 1300 Twin port

Post by 73type2 » Thu May 17, 2018 3:14 pm

Thanks Dawie. I'm currently running with a 145 mains and 170 air correction in my Brosol H30/31 carb. I also have a set of 120 mains and 110 air correction. Should I stick these smaller jets in there? I don't have a 130 main jet.

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Re: Best jets for 1971 Beetle 1300 Twin port

Post by Dawie » Fri May 18, 2018 11:41 am

That 120 main jet is too small for use in combination with the 25.5mm venturi in that carb.

Vw themselves did use smaller jetting in certain applications. Like the USA- version 1600 twinport beetle, which had 127.5 instead of the 130 main used elsewhere.
And the late 1600 bay-kombi, which came with 125 mains instead of the 130 from 1600 beetle versions. But... that 125 jet was used only in combimation with the 90deg elbow, long ducting and side-mounted aircleaner of the kombi.
Do'nt assume anything- (While doing fault-finding).
"Things should be as simple as possible, BUT NO SIMPLER THAN THAT."
"If something can go wrong, it will go wrong" (Murphy's law).

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