Author Topic: Seeking flame traps for "Star Twin" (longstroke) ?  (Read 1650 times)

Offline Stephen Foster

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Desperately looking for a pair of the above to fit 275 pre-Monobloc carbs .
They are the gauze type which would have been fitted to the short bellmouths .

Alternatively any pictures , etc please for Me to make My Own ?

Thanks in advance
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline muskrat

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #2 on: 24.05. 2014 23:37 »
http://amalcarb.co.uk/pre-monobloc/75-275-series/air-intakes/274-275-gauze-intake-assembly.html

Have a look at these, Steve.
Not cheap but could save an expensive bike from destruction.
The ones on my carbys came with them, don't know whether they are original or not.

Trev.

Offline wilko

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #3 on: 25.05. 2014 00:35 »
The last time a mate fitted one of those mesh bellmouths it ran like shit. He took it off and it was fine.

Offline muskrat

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #4 on: 25.05. 2014 03:36 »
I would imagine the gauze would richen the mixture a tiny bit but not enough to be noticeable. I wonder why it was so wilko?
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Offline Stephen Foster

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #5 on: 25.05. 2014 08:43 »
I have been told twice that this model were known to catch fire in certain circumstances & B.S.A quietly retrofitted the gauzes .
I believe the ones on Trevs bike are the original ?

I contacted Burlems & they have none left so I am scratching My head ?
I have the original bellmouths although the gauzes are long gone , still searching .
Thanks for the responses & I hope highlighting this point helps Someone else ?

I cant think of a way to make a swaged piece to fit around the outside edge of the bellmouth which would hold the gauze ?
I am open to any suggestion or offer ?

Steve ..
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

Offline Stephen Foster

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #6 on: 25.05. 2014 08:45 »
"Wilco" , If Your friend still has the bellmouths with traps I would buy them from Him & take the chance on setting My "Star Twin" up accordingly ?
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #7 on: 25.05. 2014 10:52 »
http://amalcarb.co.uk/pre-monobloc/75-275-series/air-intakes/274-275-gauze-intake-assembly.html

Have a look at these, Steve.
Not cheap but could save an expensive bike from destruction.
The ones on my carbys came with them, don't know whether they are original or not.

Trev.

It's noticeable that this is substantially larger than the intake area,  so at least Amal in 1940 gave some consideration to the restrictive effect of gauze over the intake.


The small bellmouths with gauze, that you see on "cafe racers" must be seriously restrictive.

Offline roadrocket.chris

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #8 on: 25.05. 2014 18:09 »
tried it on my twin carb rocket it went like crap i figured that if the gause was crushed to a solid it would make quite a restriction in the  venturi.
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Offline Stephen Foster

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Re: Seeking flame traps for "Star Twin" (longstroke) ?
« Reply #9 on: 25.05. 2014 20:03 »
Appreciate Your answer Chris .
I wouldnt bother with them except for the warnings I have been given regarding them catching fire .

Has Anyone else heard of this problem with the "Star Twin" please ?
I own a 1955/56 B.S.A Swinging Arm "Golden Flash" , had it since 1976 .