Bimota Forum

Vince186 · Posted: Wed Jun 27, 2012 6:44 pm Post subject: SB6 carb questions.

Hello Forum visitors,

Can someone explain to me why in my carbs there is a main jet with the size 122 installed? ( all 4 cil)
While according to the GSXR 1100 manual there should be a 125 for cil 1,2,4 and for cil 3 a 127.5 main jet.

ID number carb is 46E0

Is for the SB6 the jet size 122 normal?

Are there more deviations compared to Table for the SB6?

I want to order new parts but I’m not sure what to order. The parts that are already installed or the parts according to the Table.

_________________
vince
A person who never made a mistake never tried anything new. Albert Einstein

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

Do you know for sure if your jet's are micky roonies (mikuni) or dynojet jets?

The two makes use different numbers for the same size jet Wink

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

Vince186 · Posted: Wed Jun 27, 2012 7:14 pm Post subject:

Evilchicken0 · Joined: 12 May 2010 Posts: 2996 Location: London

Dynajets have an extra brass spacer ring that fits below the jet. They have softer narrower brass coloured needles.

I'd say the jets are different on the SB6 because the airbox is different. If you want to know which jets are going to be best then get it dyno'd, but (imho) the original jets and needles are probaly better and cheaper too.
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Don't read everything you believe

Vince186 · Posted: Thu Jun 28, 2012 8:06 am Post subject:

for everyone who has SB6….

What type carbs are placed on your SB6?
And… if you know… what size main jet are installed?
_________________
vince
A person who never made a mistake never tried anything new. Albert Einstein

Evilchicken0 · Joined: 12 May 2010 Posts: 2996 Location: London

Mikuni 40mm CV's.
My jets are different because the bike is moddified.

SB6's seem to run quite well on standard Bimota settings, there's no reason to change them unless you modify the engine / airbox / exhaust in some way and there's no power to gained from fitting a dynojet kit (in my opinion). As I said if you think the bike isn't running right have the carbs cleaned, balanced and set up on a dyno. Once you've done that you'll have a base to consider any changes.
_________________
Don't read everything you believe

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

All SB6 were fitted with 40mm micky roonies as standard Wink

The last set I had apart was on my big bore and the mains in that are 116.
The previous set were standard and 122.
I have had a set with 127......
Go figure.......who know's who has messed with them unless you've had the bike from new Wink

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

Vince186 · Posted: Thu Jun 28, 2012 4:31 pm Post subject:

Hmmmm….. I’m not the first owner….. Sad

The problem is that the bike between 3k en 5k revs is driving terrible. I mean really terrible..
It is not possible to drive in those revs. Crying or Very sad

I cleaned the carbs and synchronized them but with no result.

Now I inspect the carbs with a closer look and I noticed that the needles are worn out (damaged) That the have placed a metal washer under the needles, that’s not normal according to the GSX manual.
All the jets are damaged by wrong handling with a screwdriver…. Probably they where thinking about there mother in law while they tightening the jets. Wink

So mine idea was to replace the parts and to start again with the original settings….and see what happens than.

But can I use the settings from the GSXR 1100… Question

I can not find any setting from the SB6 or are those the same…. Question

_________________
vince
A person who never made a mistake never tried anything new. Albert Einstein

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

...If the needles are worn then the emulsion tubes will be worn oval too Wink

Metal washer under the needle clip is a fine tuning device indicating that your bike has probably been tuned on a dyno at some stage.

3K is approximately where the carb comes off the pilots and onto the main jets so, yes, this indicates your carbs are ready for some TLC. Don't forget to have them ultrasonic cleaned before you rebuild with new parts Wink

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

stockcar · Posted: Thu Jun 28, 2012 7:51 pm Post subject:

i didn't think the std Gixxer ran the same carbs as the bimota??

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

stockcar · Posted: Thu Jun 28, 2012 9:25 pm Post subject:

every days a school day.......... Laughing

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

I've been thinking...........

Because the SB6 air box is smaller (too small) than the gixxer, It follows that the bike would run too rich if you used the same size jets so it makes sense to reduce the jet size for the SB6 hence the big bore only having 116 mains and runs very well indeed with no problems whatsoever....so well in fact, I'm about to build another "big bore". All SB6's should be big bored Laughing

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

Evilchicken0 · Joined: 12 May 2010 Posts: 2996 Location: London

My bike's horrible at 3.5-4.5k is revs
_________________
Don't read everything you believe

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

It doesn't have to be........
Get it on a dyno........
Wink

_________________
SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED