Bimota SB6

[ArcanumOne]

What is the best jetting and carburetor setting for the SB6 with stock cans and air box?  I have mixture screws 2 turns out, stick idle jet #40  120 mains across all 4 carbs, needle height set in the middle 3rd level.  The bike has a bit of stumble and hesitation when warm from about 4k rpm then launches like mad…..

Edited April 17, 2022 by ArcanumOne

[Gammaboy]

On 4/6/2022 at 6:50 PM, Captain Chaos said:

I would have thought there is a breather in the tank cap.

There's a breather sat just Infront of the filler cap, with an overflow hose coming off of it. Dare say it's not working if the tank bloats. If it's building pressure, it's going to fuck with the effective float height and the fueling.

On 4/18/2022 at 12:10 AM, ArcanumOne said:

What is the best jetting and carburetor setting for the SB6 with stock cans and air box?  I have mixture screws 2 turns out, stick idle jet #40  120 mains across all 4 carbs, needle height set in the middle 3rd level.  The bike has a bit of stumble and hesitation when warm from about 4k rpm then launches like mad…..

Don't know honestly. I've set mine up to the Bimota workshop manual. Of course, I haven't even been in the same hemisphere, let alone put fuel in it for the last 2 1/2 years. Hoping to change that this year.

[Gammaboy]

Here's what the manual says. Of course, one of these settings is for the Mk1 bikes, the other for the MK2 - I guess driven by the difference in cam profiles

Edited May 3, 2022 by Gammaboy

[Gammaboy]

Oh, and here's the breather/vent

 

[BimotaMartyn]

As an ardent sb6 owner impressed at your knowledge and persistance I have 3 of these bikes all in various stages of dissasembly. Martyn.

[ArcanumOne]

Thank you for the information on carb jetting from the manual.  I have the "official" Bimota manual, but it does not have any of the info you provided.  

I have it apart again, as I discovered the Signal Generator is bad.  I bought a used one on Eblag and am waiting for it to arrive so I can install and test.

[Gammaboy]

On 5/3/2022 at 8:39 PM, Gammaboy said:

Here's what the manual says. Of course, one of these settings is for the Mk1 bikes, the other for the MK2 - I guess driven by the difference in cam profiles

I'm wrong on the difference in carb settings being Mk1/MK2 - E-04 is French market, which got neutered cams (as opposed to the inlet restrictions that some markets got).

Edited May 18, 2022 by Gammaboy

[Gammaboy]

So, almost 4 years after dropping it off to be stored at my mate's place, I picked it up yesterday and dragged it home.

Good/funny to see it again after 4 years.

Guess I better get cracking!

[Captain Chaos]

15 hours ago, Gammaboy said:

Guess I better get cracking!

Damn right

[Gammaboy]

So last night I was digging through my boxes of stuff I picked up while I was in Euwrop, and realised there was an ignition advancer there... so had a quick look at the cover and realised the factory gasket was not there, which struck me as odd for the low mileage this thing has... what's the bet that when I whip the cover off, there will be a Yosh ignition rotor in there?

 

Ordered a gasket, will pull the cover to have a look tonight.

 

Stay tuned for tomorrow's episode!

[Gammaboy]

Aaaaaand the answer is the gasket was there, everything was untouched... the bit of black sealant was from the Suzuki casebond goo that had extruded out and then been squished during installation of the cover. Anyway, 4 degree advanced rotor fitted, new gasket arrives Thursday.

[Gammaboy]

Haha, so didn't actually fit the gasket untill a couple of days before Christmas. Had planned on getting a fair bit done over the Christmas/New Years break, but between the shitty, stinking hot weather, and all the other (non Bike related) shit I wound up doing, I didn't actually touch it... However, holy shit, I did work on it today. 

Pulled the seat unit and tank, dropped the top of the radiator and swapped out the coolant pipe that had the buggered chrome that I rattle canned with black Killrust with a new old stock unit I'd picked up. Thankfully, past me had made a point of lining up all the hose clamps so I could actually get at them.

Of course, this particular pipe never sees daylight, but I know it's there....

Also swapped the mounting bracket and heatshield across from the stock cans to the factory "race" cans - tips certainly fill the hole a bit better, but I forgot to take a pic.