Captain Chaos Posted August 30 Share Posted August 30 (edited) In the old thread about carb rubbers there was quite some incorrect info. The good man @Josephoffered to write a list with known correct information, from first hand, not hearsay. So here we go: Carburetor guide to OC Suzuki bikes Collated by carburetor model, application and dimensions + info on swapping over and the use of Mikuni RS items. All this info is taken from carburetors i have been able to check or fitments i have done. VM29SS Factory "racing" flatslide carburetors. Standard fitment for GSXR 750 85 to 87 Stub OD : 40 Airbox OD : 50 Same exterior dimensions as BST34, they can be swapped over plug and play. Apparently it has also been common practice to overbore the 29s to 32-33mm BST34 Standard fitment on GSXR 1100 1986-1988 and GSXF 1100 all years Stub OD : 40 Airbox OD : 50 These swap over plug and play on the GSXR 750 85-87 BST36 Most used carburetors throughout the OC range Standard fitment on Bandit 1200 (mk1), GSXR 750 1988-89, GSXR 1100 1989-90, GSXF 750 1988-1998 (mk1) GSX1100G all years Stub OD : 42 Airbox OD : "Ovaled" shape > 58 width, 63 height BST38 Only used two years on the GSXR 750 1990-1991 Stub OD : 46 Airbox OD : 58 They are give or take underbored BST40s, they swap over plug and play on GSXR 1100 1991-92 BST40 Standard fitment on GSXR 1100 1991-92 Stub OD : 46 Airbox OD : 58 Swap over plug and play on GSXR 750 1990-91 Mikuni RS carburetors They are sold with a 77-93-77 spacing, bear that in mind when it comes to fitting them on, because GSXR etc carburetors have a 78-90-78 spacing, requiring some massaging to slip them on, to, preferably, new inlets when available RS34 Stub OD : 40 Airbox OD : 55 (Note that they are also available with a 42mm stub OD) The 40 OD will go on BST34 bikes/inlets The 42 OD will go on BST36 bikes/inlets RS36 - RS38 These both have the exact same exterior dimensions Stub OD : 42 Airbox OD : 55 They share the same stub dimension as BST36 carburetors RS40 Stub OD : 45 Airbox OD : 55 Slightly smaller than the BST40 carburetors, your only way to fit them is by using BST38-40 inlets and giving them a bit more tightness with the clamps For all RS : Sleeves are available to fit to the airbox side of the RS carburetors, to reach 58mm for oem fitment to enable airbox fitment where applicable. To break it down : RS 34 can fit BST34 bikes/inlets (or BST36 bikes if using the ones with a 42mm stub) RS36 and 38 fit any bikes/inlets using BST36 RS40 only fit bikes/inlets using BST38 or BST40 Inlet rubbers - general info It is always best to use new items, or renew them (although most are no longer available as we speak) They harden up over time and with fuel contact, and will have a tendency to shrink. When new, they are approximately 1mm smaller in ID than the carburetors they fit, for obvious reasons. It is best when storing unused inlet sets to leave them fitted to a matching rack of carburetors GSXR WC carburetor conversion Oil cooled engines have a carburetor spacing of 78-90-78 WC engines have a carburetor spacing of 85-90-85 The GSXR 750 WC uses BST38 carburetors which is interesting for OC bikes. The spacing being different compared to oil cooled engines, this mix can make them compatible in order to fit OC heads : Spacing between cylinder 2 and 3 is the same, so just use the WC inlets In order to make up for the difference in spacing on the outer carburetors, if you use an inlet nº3 on cylinder 1, and an inlet nº2 on cylinder 4, you'll almost catch up the right distances and the WC carburetors will go on. Specials : Bandit 1200 mk2 use BSR36 carburetors with a different spacing to the other OC engines, you would need to swap over the specific inlets with the carburetors for them to fit anything else The GSXF 750 mk2 use BST36SS carburetors, they have the same spacing as mk1 and OC engines, and same 42mm stub as the BST36, but they have 58mm round stubs on the inlet side, making them ideal for pods/turbo applications Edited August 31 by Captain Chaos 14 Quote Link to comment
Gixer1460 Posted August 31 Share Posted August 31 Quote Standard fitment on Bandit 1200 (mk1), GSXR 750 1988-89, GSXR 1100 1989, GSXF 750 1988-1998 (mk1) GSX1100G all years GSXR 1100 1989 AND 1990! Quote Link to comment
Captain Chaos Posted August 31 Author Share Posted August 31 2 hours ago, Gixer1460 said: GSXR 1100 1989 AND 1990! edited Quote Link to comment
bunk Posted September 8 Share Posted September 8 Are there any new carb rubber suppliers that work? Ive heard chinese rubbers are not worthwhile, what exactly is wrong with them and is it possible to tune them up to work? Quote Link to comment
DAZ Posted September 8 Share Posted September 8 Thanks for the update and the measurements , in the specials section did you mean the mk2 gsxf750 has bsr36ss carbs spaced as the bst ( earlier o/c ) type ? As every thing I've read says post 98 teapot750 are bsr Quote Link to comment
Upshotknothole Posted September 8 Share Posted September 8 3 hours ago, bunk said: Are there any new carb rubber suppliers that work? Ive heard chinese rubbers are not worthwhile, what exactly is wrong with them and is it possible to tune them up to work? They're not a full set, should be 4 unique intakes, instead they give you two of the same left and two of the same right intakes. Quote Link to comment
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