b12 carbs on 1127

[carl t]

Hi all! I recently discovered my bandit motor is in fact a '91/'92 1127 gsxr lump running bst36mm carbs with stock b12 jetting. Had some carb issues when winter struck and after cleaning them,new air filter,plugs etc cant quite get it running sweet at low revs. its not too bad but suspect jets/needles becoming worn so can anybody recommend what size jet kit to install and whether or not to junk the airbox bearing in mind it is my daily ride and dont wish to create a monster!! Bike also has (I think) gsxr750 4-1 with cut down stubby offering no back pressure which I will be replacing (which does run better lower rpm when I pop a db killer in). Thanks in advance guys

 

[Gixer1460]

Have to ask the obvious - if its a GSXR1100 M/N (which should have 40mm CV's) why not change the jetting to match an 1100 K/L which used 36mm CV's - not Blandit - totally different requirements? The 36's are easier carbs to tune and work brilliantly with a GSXR engine - 125hp stock against 100hp from Blandit.

[carl t]

Haha yes I understand its a little obvious but  it doesnt hurt to ask people who've been there and done it!! anyway, how about the airbox? stock, mangle or get rid altogether? and  thanks!!

[boilerdude]

mangle and tune with gorilla tape. 

[Oilyspanner]

Tuned B12 motors need a modded a.box, so it's going to struggle with the higher revving, air hungry 1127 engine. Dual pod filters would be easiest option, then you would need a jet kit to suit ie one for 1100K/L, with 36mm carbs - it's easy to get the main jet and pilot jet size about right, but the needle is very difficult and best left to factorypro/dynojet, who've done all the hard work for you. You can spend weeks/months trying different needles etc to get your altered bike's carburation sorted, always ends up easier to buy a kit - it normally saves time, money, marriages, mental health and a variety of other health issues !

[Venom]

maybe you have gsxr 1100  36mm carbs 91/92 but US version .

[carl t]

thanks guys! defo bandit carbs/jets. had to raise float heights to cure low end bog, ran pretty decent till I fitted correct sprockets and now its lean as fook if I whack the throttle open with the improved urgency in the gearing. there seems to be loads of horror stories about using stage 3/pod filters regarding low rpm running etc. may plump for stage 1-3 then it should give me more to play with, plus theres always boilerdudes gorilla tape method -right up my street!!!

[boilerdude]

If its gsxr it will have 2 fuel hoses. You have 2 main hoses one is feeding carbs 1 and 2 and 1 hose is feeding carbs 3 and 4.  Bandit just has 1 fuel hose to serve all 4...