Mikuni BS36 CV carbs for XS1100

[makzy]

Sorry yes they do Brian, was getting confused with the early carbs, Here's something else, the bowles from the later 34's won't fit the early carbs, the tube for the choke fuel pickup is about 2mm off..

[AussiXS11G]

This is the first set of carbs that I have used fuel levels rather than float heights.....I set float heights
to begin with but found that I was getting uneven fueling...... No 2 son (and Xtian, Steptoe and others)
all pointed out the error of my ways.....
It would appear that the brass floats of the BS34's all had the same volume and weight while
the plastic floats of the BS36's do not.....
Do your BS36's bowls not allow for checking fuel levels?

[makzy]

Yeah did mine in too, i'll have to make some plugs with nipples to take a hose to measure fuel levels, thanks...

[AussiXS11G]

yes Makzy
the plugs came with the kits but I have lost a couple of them already....
that breather thing did my head in for a few days there 4 sure...
I set fuel level rather than float height at between 4.5mm and 5.5mm below float chamber line...

[makzy]

Just been reading back thru the thread about bs 36 carbs and read where Brian had an over fueling problem that was fixed by putting the bowl breather pipes back on to the air box. Well i've just discovered the same thing, I had fitted a set of early carbs out of the us, all in spec with the book as far as jets and needles float height and everything, bike ran very well while on the stand, ballanced the carbs, tuned it, SWEET, took off down the road and it just refused to run over 4500 revs, just seemed to 8 stroke like too much fuel, so out came the 137.5 mains and in went 125's much better, but not rite, so thought i'd tidy up a few things while i tried to figure what to do next, thought i'd put some pipes from the bowl breathers to the air box just to keep the crap out, and tidied up my fuel lines a bit, went for ride and like Brian said, Hey Presto!!!went like a rocket, so i thought, put the 137.5's back in, Magic!! i've never had those breather pipes hooked up before as i'v had late carbs that vent thru the carb throut, so now i'm going to try the Bs36's with bigger jets and the breather hooked up and see what happens..
By the way Brian, do the BS36 carbs have to have the little rubber plugs in the pilot jet holes? mine never had any but looking at a tutorial it shows them and it also says the float height should be 22.4.. what do you think??

[petejw1966]

no worries bryan,
just a hint don't go running the float levels lean,
that'l start causing all sorts of problems, holes in piston is just one of them.

[AussiXS11G]

I believe so Pete
I have had the carbs off and on a few times since we last forumed.....
While the jets/needles are the same I have fiddled with float heights, needle positions,
fitted iridium plugs and colortuned......
having said all that, I will pull the plugs tomorrow and report back......

[petejw1966]

hey bryan,
did you sort out the lean running?

[AussiXS11G]

well now - see what I found.....
this from August 1997



when the bike looked like this - was basically bog standard with over 100k kms

[petejw1966]

hey bryan,
yeah u want a nice complete even soot ring  (to heavy and ur running rich)
like in the pic of the 1st plug, otherswise ur running lean,
just screw out the mixture screws a little on 3 and 4 and u should be sweet to go,

[AussiXS11G]

hello Pete
They weren't wiped - but they are all equally sooted - the soot does not form a full ring tho -
I suspect had the plugs been dialled this would be more evident
should the sooting be continuous around the base or is it a feature of the exhaust side of the cylinder do you reckon?
B

[petejw1966]

hey bryan,
the plugs look good
tho 3 and 4 looks a little lean,
u want the black soot to cover the base ring evenly like in the 1st plug,
unless the plug was wiped before u took the pic,
open up the mixture screws a little more on 3 than 4.

[steptoe]

Gotta be happy with that,,   

[AussiXS11G]

swapped out my plugs for the first time since Nov 2012....
1 to 4, L to R





all looks good to me - still running great 

[makzy]

Thanks will try and chase up some jets and give it a go,