Best S.R. /RGS NEW carb option?

[Kickaha]

There's a half-decent Mikuni there too, -I'd need to make a flange adaptor. Not such a big problem. Food for thought.

No you wouldn't
https://mikunioz.com/shop/mounting-flange-for-mikuni-35mm-spigot-to-amal-stud-spacings/?v=13b249c5dfa9

[Joolstacho]

Thx for that Kickaha, But $120 plus postage for the adaptor is a bit rich doncha reckon? I know I'm ol' school, (read tightarse!) but! (It's for a 28mm anyway).
Yes, my monobloc is 28.4mm, I even have a Mk2 Concentric but it's 28mm too. The worn Mk1 Concentric on it is 30mm.

The motor is about RGS tune (has 9:1 comp ratio -measured). I'm thinking that I need 30mm if I want full throttle performance.
Mikunioz don't have a 30, they have 28 and 32. I can get 30 from US but postage is a killer.
Maybe a Concentric 1.5? (Is that what they call a 'Premier'?)

Anyone tried one of those? I've got plenty of jets etc for them.

[Rex]

The Premier is a similar design to the Mk 1 other than the pilot jet is external and easily removable (and comes in a range of sizes)  and the slide is hard anodised.
I don't know how the Mk1 differs from a Mk 1.5 though.

[JulianS]

The Mark 1.5 is quite different from the concentric, has a completely different cold start circuit with no tickler.

Dont think they are still being made,

[berger]

hi col the only thing is a 5/16th hole drilled through the shaft for the roll pin, you can see the saw blade line that i used to line it all up for drilling, many moons ago when i was a lad

[Kickaha]

Thx for that Kickaha, But $120 plus postage for the adaptor is a bit rich doncha reckon? I know I'm ol' school, (read tightarse!) but! (It's for a 28mm anyway).

I pay what gets me the part that I want, compared to what the bike is worth or what you've probably spent on it then it's a small cost, I know it is with me

28mm Mikuni has a 35mm OD on the engine side so fits that adapter, 30mm carb has a 40mm OD and fits the other one that they do, If I go the Mikuni route for my A10 I'll fit the 30, it isn't a big carb for a 650 motor and Mikunioz do a 30mm VM
https://mikunioz.com/shop/vm30-83-30mm-vm-carburetor/?v=13b249c5dfa9

[RDfella]

I'll fit the 30, it isn't a big carb for a 650 motor and Mikunioz do a 30mm VM

In my view, 30mm would compromise acceleration. Remember, it may be a 650, but it's not a single, the carb is only feeding 325cc at a time. My suggestion (unless the bike will be spending most of its time at 4,000 or above, would be 28mm (1 1/8")

[muskrat]

I'll fit the 30, it isn't a big carb for a 650 motor and Mikunioz do a 30mm VM

In my view, 30mm would compromise acceleration. Remember, it may be a 650, but it's not a single, the carb is only feeding 325cc at a time. My suggestion (unless the bike will be spending most of its time at 4,000 or above, would be 28mm (1 1/8")

DOH! My cafe breaths through TWO 30mm PKW's. Yes mostly above 4 grand, but that's when the 357 starts to work! 
Cheers

[chaterlea25]

Hi All,
The Mikuni I have on my SR is 30mm, It works like a charm 
The 30mm carb has a bigger body than the 28mm so it needs a pancake type air filter to fit in the space available.
The 1549 or 1571 alloy heads can either have 1 1/8in. or 1 3/16in. inlet tracts, fit the carb size to match the head

John

[Joolstacho]

I'll fit the 30, it isn't a big carb for a 650 motor and Mikunioz do a 30mm VM

In my view, 30mm would compromise acceleration. Remember, it may be a 650, but it's not a single, the carb is only feeding 325cc at a time. My suggestion (unless the bike will be spending most of its time at 4,000 or above, would be 28mm (1 1/8")

This is the answer I got from Mikunioz:

"Maybe out of those waiting on a new shipment
You’ll have to look at Mikunioz (?) as will need a full jet set to work on your motor where we do not sell tuner kits here".

30mm not in stock... -(and they don't sell 'Tuner kits').

[Colsbeeza]

Hi Berger,
That is a novel approach. Looks to have plenty of length.
Col

[Kickaha]

The Mikuni I have on my SR is 30mm, It works like a charm

Do you know what jets and needles etc it is fitted with ?

[Joolstacho]

Haha Kickaha!...Quote:
"I pay what gets me the part that I want, compared to what the bike is worth or what you've probably spent on it then it's a small cost,..." End Quote.
Oooh but what if the kids need new shoes as well?
There's food for thought eh?

[rocker21]

have you tried one of the JRC cabs from the USA, comes in a range of sizes and i have fitted them to lots of brit bikes from bsa bantams, up to many 650 twins and even a rotax engined bike, its a very simple carb and easy to setup. and norton comando!!! got one on my own A7ss
i sell them here in the UK

[Joolstacho]

Well mate it could be a good call. I've used them on a couple of Trials bikes with success.
I was a little concerned whether I could get the info and parts to get one tuned in properly.
Do you have the settings etc for a Super Rocket? (8.75:1 - a little higher comp than standard)
There are a couple of horror stories because of parts and info.
I'll have to see if there's a seller from Asia or in Australia.