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knuckle head
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Originally Posted by Allan G
An A65 race bike next?
Triumph racers, do not let other Triumph racers ,ride BSA race bikes wink grin


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
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kevin Offline OP
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no no the next project iz the T120 track bike. idbe hopeless trying to make aBSA go fast

but i still need to take the correct tank for this 66 and fix the hole in it.

itz got some putty over the spot where itz leaking, and i may just clean it off and put on new putty. depends on how bad it is underneath


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They should have made a bike called the Cyclobolt.

Could have saved the British bike industry.


Amateur Loctite enthusiast.
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I rather liked 'Thunderclone' myself.
Stick an a10 crank in and you have a Thunderflash.

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kevin Offline OP
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whatever it is it runs really well now

courtesy of an ignition that cost about a quarter of what i paid for thewhole thing to start with

but it doesnt need anything else and is great fun to ride. thiz one isntfast but its loud so who cares. i have fast stuff elsewhere


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knuckle head
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Originally Posted by NickL
I rather liked 'Thunderclone' myself.
Stick an a10 crank in and you have a Thunderflash.
How about Thunderocket how cool is that? Yes ,a A10 crank and A10 rods to go with it...I have a pile of A10 rods.....But for some reason, like they are all unsuitable for use, I just spent $450 on a new set....


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
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Apart from cleaning up your inventory, why would you use the 6.5" A10 rods? one of the hot rod solutions was to use 6" rods, plus with a standard barrel and A70 pistons you have an instand 750cc at +0.020" oversize.

I think Thunderbolt Rocket was the original name for the Thunderbolt back in 64/65 in the US Market, Over here we just called it a Rocket. 20:42 gearing and sports camshaft (68-473) I beleive over the standard Star model. Geared quite tall compared to later bikes and even the Lightning Rocket brother, it would pull 100mph @ 6000rpms calculated (not sure what the actual top speed was)


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

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knuckle head
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Originally Posted by Allan G
Apart from cleaning up your inventory, why would you use the 6.5" A10 rods? one of the hot rod solutions was to use 6" rods, plus with a standard barrel and A70 pistons you have an instand 750cc at +0.020" oversize.

I think Thunderbolt Rocket was the original name for the Thunderbolt back in 64/65 in the US Market, Over here we just called it a Rocket. 20:42 gearing and sports camshaft (68-473) I beleive over the standard Star model. Geared quite tall compared to later bikes and even the Lightning Rocket brother, it would pull 100mph @ 6000rpms calculated (not sure what the actual top speed was)
Duh, I was thinking of something else, you are correct.
Sota interesting BSA used US and Brit aircraft names....


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
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Originally Posted by kevin
whatever it is it runs really well now

courtesy of an ignition that cost about a quarter of what i paid for thewhole thing to start with

but it doesnt need anything else and is great fun to ride. thiz one isntfast but its loud so who cares. i have fast stuff elsewhere


That's typically the way these days Kevin, most blokes rebuilding these old heaps tend to spend 3 x the purchase price
on the rebuild, regardless of whether it's needed.
As an aside, i think a 230 main was the setup for a standard t'bolt i wouldn't go any smaller than that if the bike's
going to be ridden any distance.

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i'll see. only takes a moment to test. i have a 230 in the mystery carb i stole the number three slide from.

still curious as to whether i could make a mikuni fit. there's a two-inch bolt-center flange-to-spigot adapter in the mail as i write.


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Originally Posted by Hillbilly bike
Sota interesting BSA used US and Brit aircraft names....
Thought they were all named for natural disasters or pests.
Lightning, Thunderbolt, Hornet..... laughing


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
72 T120V cafe project "Mr. Jim"
72 T150V "Wotan"
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Originally Posted by DavidP
Originally Posted by Hillbilly bike
Sota interesting BSA used US and Brit aircraft names....
Thought they were all named for natural disasters or pests.
Lightning, Thunderbolt, Hornet..... laughing

Likewise I assume the model series were named after British Roads (A10, A65 etc)


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

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Originally Posted by Allan G
Likewise I assume the model series were named after British Roads (A10, A65 etc)

Yeah and the D1 was named after Prince Charles’s first wife!


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Originally Posted by triton thrasher
Originally Posted by Allan G
Likewise I assume the model series were named after British Roads (A10, A65 etc)

Yeah and the D1 was named after Prince Charles’s first wife!

laughing


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

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well, now that the thunderclone is running well, it's time to experiment and mess it up. this 2-inch-on-centers spigot mount just arrive from MAP. US$21, i think it was.

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]

it's also only 0.70-inches thick, front to back:

[Linked Image from i.imgur.com]

OD of the spigot is 1.545, which matches a 32-34mm VM mikuni exactly.

[Linked Image from i.imgur.com]

ID tapers from 30 to 29mm or so:

[Linked Image from i.imgur.com]

this might be skinny enough to test a spare 32mm mikuni on the A65.

[Linked Image from i.imgur.com]


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You may get away with that on a pre oif one.

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dunno, nick. im just curious now

the 2-inch to spigot manifolds used to be rare and expensive . im interested in seeing if i can fit something on the 66 A65.

if i cant get an air filter in there ill see about the 441 instead


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ah, well the short answer is that th emikuni will fit, but not with any filter that i have available.

here;s the spigot. had to file the mounting holes a bit, but it fits fine

[Linked Image from i.imgur.com]

and here's a comparison of the two possibilities. the AMAL is definitely the shorter of th etwo instruments

[Linked Image from i.imgur.com]

with no filter in place, the miuni fits in betwen the head and the oil tank with clearance. only about an inch between th ebellmouth and the oil tank, but it will go on

[Linked Image from i.imgur.com]

but with the pancake filter i have, i'm short about 3/8-inch of non-negotiable space.

[Linked Image from i.imgur.com]

so, the perfectly satisfactory AMAL goes back on the thunderclone, and the mikuni will go somewhere else someday.

this is th efilter that won't quite fit. at one time you could purchase mikuni kits that had a filter even thinner than this, but i haven't seen on ein a long time.

[Linked Image from i.imgur.com]

the filter element on this measures 1.215-inches. kevin victor elsewhere sugegsted MAP,, and i just looked at their Lightning mikuni kits:

[Linked Image from i.imgur.com]

hard to tell, but ^^^this may be the thinner filter that i remember seeing. i'll have to give them a call.


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Kev,

I've just bought some Mikuni type adapters that will fit 2" hole centres.

Try this website.
http://www.motocarb.com/adapters--connectors.html

I've bought 2" x 32 x 40 x 5/16" for some VM32 - they fit fine.

£26 each ( ! )

But you can probably buy the same in the US, I just Google Mikuni adapters and sniffed around.

When you install the carb in the adapter and it's seated it basically adds 10mm to the front of the carb.
The adapter you have looks about 18mm so the gain is 8mm so it might give you what you need. .

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kevin Offline OP
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yo, maybe that would do it. the MAP spigot is 0.798-inches, which is 20mm, and with a guesstimate of 3/8-inch needed, i'm looking for an extra 9.5mm, close enough to 8 for me.

that british flange and a thinner filter might do it. but i confess, twenty-six pounds for one is steep at the moment.

i'll look around on this side. i've seen some bodgy solutions, but nothing as tidy as that.


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i use the Mikuni adaptors, they never get any cheaper, cos of the weird Brit stud spacing nothing else works, they are V handy where space is critical. They last about 5 years before splitting if left unsupported, also the carb starts to droop in a down at heel sort of style, eventually i sort of fixed that with carb to airbox rubbers which bear some of the weight, your pancake filter will make it worse, a bungee cord is a simple but bodgy fix.


71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
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gavin, what are you using them on? youve got Concentrics on your 71, and im not familiar with your other stuff.


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My head is modified, did it years ago back in the 80s, instead of the flange mount I have steel spigots screwed into the ports, i bolt the flange side of the adaptors to the Conc carb . It s this way because of the lack of clearance,
did this after doin similar mod to my mates bonnie, trying to get rid of vibe induced fuel frothing, kills two birds , no frothing , no heat issues, carbs are easy to get on and off without disturbing the easily distorted flange.
The Bonnie was V reliable when racing,flat top pistons, careful assembly, always finished, V short gearing, great on short twisty tracks , rubbish on fast tracks.Always finished though. no funny cams , only long reverse cone megas, stock headers, with the US bars and peanut tank, looked like he had got lost goin to the shops. If you look close at the motor pics in my long thread they are pretty obvious, the big break through was finding the later t140 airbox rubbers which allowed the airbox to connect, before that it was shorty bell mouths droopy, carbs and fast wearing rings.

Link to start of my rebuild saga , lots of pics of the spigots/head http://www.britbike.com/forums/ubbthreads.php/topics/541665/2

Last edited by gavin eisler; 10/15/20 8:09 pm.

71 Devimead, John Hill, John Holmes A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
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knuckle head
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My little mind thinks extremely thin ar filters can cause tuning issues.


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
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kevin Offline OP
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i remember. those airbox rubbers were always a pain inmy 650, but they work.


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