Throttle Butterflies on Solex 40 PII Twin Shaft Carburettors

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Rene Santos
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Posts: 46
Joined: Thu Oct 21, 2010 7:49 am

Throttle Butterflies on Solex 40 PII Twin Shaft Carburettors

#1 Post by Rene Santos »

Gentlemen,
I am in the process of rebuilding my S 90 carbs fitted with twin shaft 40 PII carbs. Part of the rebuild is to convert to single shaft. I will be re-machining the carb bodies since there are score marks on all the bores. My question is relating to the butterflies. Should the butterflies at any time come in contact with the bores of the carburettor? Obviously with mine they have hence the scoring. But if the throttle shaft bushes are new and the shimming of the shaft is correct, is it normal for these carbs to fully shut closed in the rest position? Thank you
Rene Santos
356B S90 Coupe
991 Turbo S
Harley Davidson CVO Street Glide
Location UK

Dick Weiss
356 Fan
Posts: 4183
Joined: Sun Apr 20, 2008 12:54 am

Re: Throttle Butterflies on Solex 40 PII Twin Shaft Carburettors

#2 Post by Dick Weiss »

Oversize throttle plates or not, the edge(s) must be matched in line to the 1st or 2nd bypass hole(s)
in the throats so you'll get proper balance @ the idle and low RPM position.

Rene Santos
356 Fan
Posts: 46
Joined: Thu Oct 21, 2010 7:49 am

Re: Throttle Butterflies on Solex 40 PII Twin Shaft Carburettors

#3 Post by Rene Santos »

Sir ,
Thank you for your response much appreciated.
Rene
Rene Santos
356B S90 Coupe
991 Turbo S
Harley Davidson CVO Street Glide
Location UK

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