Venturi gauze

Information relating to the Matchless G9 or AJS Model 20 500cc twin
SPRIDDLER
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Re: Venturi gauze

Post by SPRIDDLER »

Eamonn wrote: Tue Jun 08, 2021 11:56 pm I recall reading somewhere that the primary purpose of these gauze covers was to prevent fires in the event that the engine "spits" back into the carb.
Alternatively, follow the instructions in the '49 Owners Manual........


Carb fire 1949 Owners Manual 2.JPG


but there's a risk...........


JLL.jpg
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ajscomboman
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Re: Venturi gauze

Post by ajscomboman »

They don't have any effect on the jetting. All my bikes for the last 30+ years have had them on and none have deviated away from standard main jetting other than the pilot jet on the odd 1 or 2, but that isn't directly related to the gauze. More just down to slight wear and different fuel.
Simkat
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Re: Venturi gauze

Post by Simkat »

ajscomboman wrote: Wed Jun 09, 2021 10:49 am They don't have any effect on the jetting. All my bikes for the last 30+ years have had them on and none have deviated away from standard main jetting other than the pilot jet on the odd 1 or 2, but that isn't directly related to the gauze. More just down to slight wear and different fuel.
That's good to know, thanks very much!
Andy51
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Re: Venturi gauze

Post by Andy51 »

Made no discernable difference on my AJS, the mesh is too coarse to affect airflow significantly. Andy
Mick D
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Re: Venturi gauze

Post by Mick D »

Hmm!

You could look at this from the point of view that the mesh in the OP's photo is reducing the area of the inlet by around 10% - I'll stick with open bell mouths.

Regards Mick
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ajscomboman
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Re: Venturi gauze

Post by ajscomboman »

Trust me Mick it makes no difference at all.
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