Bimota Forum

sb6rdaz · Joined: 23 Nov 2010 Posts: 124 Location: Burton-upon-Trent

Gotta ask, why 122.5 main jets? They're way too small for the GSXR1100W motor, typically they need 140's at least when running them on my Dyno. No need to stagger them tho, I ran my 6R with 4 Lambda sensors, 1 in each downpipe, and they all were so close as not to need any difference at all.
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Mako · Posted: Tue Oct 30, 2012 8:00 pm Post subject:

sb6rdaz · Joined: 23 Nov 2010 Posts: 124 Location: Burton-upon-Trent

But they are Dynojet 122's that are refered to, not Mikuni 122.5's, the sizes do not equate to the same thing at all. That said, Dynojet 122 or Mikuni 122.5, both are too small to fuel the SB6 anything like effectively. They are also being used with Dynojet needles too, which can alter the main jet needed too by quite a margin.
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CBar · Joined: 05 Jan 2010 Posts: 142 Location: Texas

The Suzuki manual shows '94 models in certain countries having smaller jets on #2 and #3. Later years show larger jets for 2 and 3 compared to 1 and 4. Bimota installed larger jets than Suzuki.

sb6rdaz · Joined: 23 Nov 2010 Posts: 124 Location: Burton-upon-Trent

The Suzuki manual holds little relevance when considering jetting and carburation, as the airbox and exhaust are very different when installed in the Bimota. And I'd suspect that Bimota maybe jetted them with an ounce of a safety factor in there, so the bike would fuel acceptably in all markets, so wherever in the world it was shipped to, running whatever fuel, with all the other variables too thrown in. That is still very evident on current bikes.

When on good quality but regular UK pump fuel, the bikes I have had on the dyno have all benefitted from a downsize in main jet.

I also looked into the size differential across the cylinders, and found them to run very close to one another, my 6R runs the same main jet size across all 4 cylinders, so the cooling of the water cooled 1100 engine seems to be steady across all 4 cylinders. Usually the size differential is to allow for the centre 2 cylinders running hotter, but in the engine in question there was no such need at all. Cetainly a lot of vee twins run different fuelling for that exact reason.
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It's mine and I'll wash it as fast as I like!

Mako · Posted: Thu Nov 01, 2012 12:01 pm Post subject:

As suggested I changed the order at Wemoto.

today I was checking float heights and I've noticed some float needle pin was stuck.
In a bath of WD40, a gym work to the pin with a little screwdriver (some rusty crap coming out from the pin) and now they are ok again

a diaphragm is slightly bent on the flunnel... but I guess it would work as it is not gummy
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

Mako · Posted: Thu Nov 01, 2012 6:37 pm Post subject:

fixed the needle pins I've noticed a broken float. Not the float itself but the retaining piece on the choke system side:

broken:

good one:

I'm wondering if I could fix (the missing piece only use the bowl to let the float in place) or try to find a new one..

on Ronayers I found two different part codes for the float... and both very expensive... anyone knows the correct one?
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

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

..I may have a spare if you need it Wink

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

Mako · Posted: Thu Nov 01, 2012 6:51 pm Post subject:

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

Mako · Posted: Sat Nov 03, 2012 6:16 pm Post subject:

Mako · Posted: Wed Nov 07, 2012 12:38 pm Post subject:

Cooling system.

changed water pump cover, new Samco Hoses, will clean thermostat but not omitt it as in first istance, cleaned radiator an metal pipes.
The last thing I would like to do while I have the engine off the bike is to check, change the radiator cap.

As maybe you remember, my SB6 overheated quite fast... and one of the causes could be a faulty radiator cap. I haven't the proper radiator cap checking tool, but I think It would not be a bad Idea to replace with a new one:

Uploaded with ImageShack.us

It is a 0.9 bar one and I guess it's an easy to find spare part...

anyone knows where it comes from (other bikes, maybe cars....)?
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Honda CB450K1 - CB750K2 - CB500K1 - RC30 - Ducati 750SS - Bimota SB6

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

Marco...please take a picture of slightly further back on the engine, in particular, the metal cooling pipe.
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SB6 mk1 (project mega light, big bore)
Sb6 mk2 ( Big Bore)
Sb6 mk2 ( Restored)
Sb6R fighter
Sb6 or Sb7 WANTED

Mako · Posted: Thu Nov 08, 2012 7:19 am Post subject:

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

I think you should get some autosol on it Razz

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