Author Topic: Concentric 930  (Read 697 times)

Offline Topdad

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Concentric 930
« on: 24.05. 2022 12:31 »
Hi fellow BSA mentalpieces , anyone tell me the correct (approx ) adjustment for a concentric pilot jet ,had to strip the carb to clean out tne crude and lost count of turns to take the screw  out ,any help appreciated as always ,cheers Bob
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Online Triton Thrasher

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Re: Concentric 930
« Reply #1 on: 24.05. 2022 13:54 »
1.5 turns as a starting point on a Mk 1 Concentric.

Offline Topdad

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Re: Concentric 930
« Reply #2 on: 24.05. 2022 15:00 »
many thanks TT
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Offline muskrat

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Re: Concentric 930
« Reply #3 on: 24.05. 2022 21:19 »
G'day Bob.
As TT said 1,1/2 out is the starting point. Depends on the state of tune, pipes, air filter (or not) and size of carb.
On my A7 with a 32mm Mk1 it's 2,1/4.
It's really a trial thing once the motor is up to operating temp. At idle wind out 1/4 at a time, let it settle and give a few blips. Do this til she starts to 8 stroke then wind it back till she falters. Half way between the two should be just right.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Muskys Plunger A7

Offline Topdad

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Re: Concentric 930
« Reply #4 on: 25.05. 2022 11:54 »
Cheers Musky *smile*
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Offline KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
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Re: Concentric 930
« Reply #5 on: 25.05. 2022 21:49 »
Hi fellow BSA mentalpieces , anyone tell me the correct (approx ) adjustment for a concentric pilot jet ,had to strip the carb to clean out tne crude and lost count of turns to take the screw  out ,any help appreciated as always ,cheers Bob


You probably know...but cleaning out the idle jet circuit on the concentric is a bit of an art, involving either a very small drill or thin wire....and a bit of luck  ;)
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1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
1968 B44 Victor Special (3rd finished project)
2001 GL1800 Goldwing, well, the wife likes it
2009 KTM 990 Adventure, cos it’s 100% nuts

Offline Topdad

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Re: Concentric 930
« Reply #6 on: 26.05. 2022 10:54 »
Yes thanks Kiwi,  had a plastic hearing aid cleaner to hand and that seemed to work well but we'll see,cheers Bob
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Offline Topdad

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Re: Concentric 930
« Reply #7 on: 16.06. 2022 14:37 »
Many thanks evevyone for info, on sunday my bike started after over 2 yrs , haven't ridden the bike yet but will soon, then I'll see but initial signs are spot on at 1 1/4  ,she was ticking over a little slowly but will soon sort that overall  just great to her her going again,Bob  *beer*
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