Mikuni BS36 CV carbs for XS1100

[McShafty]

has anyone tried this conversion? i found a bit on them in the assie forums. they mentioned running 140 jets. but talking to the a supplier they have never heard of needing such a large jet.

[skids]

I have bigger ones in my 78E with a Jardine 4 into 1 header and K&N individual air filters. It is still too lean at WOT.

[TomB]

I use BS36 MKIII Mikunis, you have to use a much bigger main jet because air flow velocity is slower on a bigger choke size when used on our bikes (the carb bore, not the thing that helps it start when cold), the bigger choke size causes slower air speed and therefore less venturi effect on the needle jet causing weak mixture. I have fitted CB750 carbs to a CB77 and had the same issues

On standard XS1100 early carbs, the MKII BS34's, 132 mains are fitted, I have used those in my MKIII BS36's but still need to up a few sizes, so 140 sounds about right.

Your supplier may be referring to standard use of these carbs when saying he's never heard of needing jets that big.

My BS36's came from an FJ1200, I also have a set from a XJR1200, doubt you'll get those over your side though



.

[LoHo]

Skids, with large jets and wide-open air flow, what sort of MPG do you see?

[skids]

Skids, with large jets and wide-open air flow, what sort of MPG do you see?

Ooodles of low end torque (fun), about 38mpg city and 32 highway. This is at one mile high.

[McShafty]

ok ill give the 140s a shot. my experince with carb mods is limited so bear with me lol

[skids]

Ooodles of low end torque (fun), about 38mpg city and 32 highway. This is at one mile high.

I should have also told you that these were the original style carbs.

[XrockerS]

This sounds like what I wanted to read! Tom B I have a set of BS36 on my Xs nd i'm wondering what would be a good place to set the floats at? do you remember what yours were set at? I haven't checked my jet sizes but I will soon. another thing I was wondering is what are you doing to accommodate the vacuum advance?