Buzuki

No ,bigger oil pump for high pressure engine lubrication loop directs oil flow through the Oil Filter Patrone , and that`s the Filtered oil , but second smaller oil pump for low pressure cyl.head cooling loop do not directs oil flow through the Oil Filter Patrone to be filtered , and that`s the whole difference . ps, of course that both oil pumps takes the same unfiltered oil from the same oil pan.

Unfiltered oil use the smaller oil pump , which basically sucks the oil from oil pan which is further distributed via two hoses up to the cylinder head cover , and further to 8 big oil jets which splash and cools thermally very loaded points on aluminium cyl.head , finally that but now heated oil falls down in the oil pan via on the engine front placed two big oil metal pipes and two stud bolts , that`s how oil head cooling circulation loop is done , btw, those from the front two oil metal big pipes have also the function as some sort of minor oil cooler , since majority from the cyl.head returning heated oil pass through them , it is important to notice that cyl.head oil cooling loop have almost no any oil presure but have very high rate of oil flow, if I remember correctly for very early slabby 750R engine that`s about 52L/min. at full engine load and at max. RPM , without this oil cooling system aluminium cyl.head will be melt down very quickly , as for engine lubrication system there`s another bigger one oil pump which sucks the same unfiltered oil from the same oil pan , but now under pressure the oil goes to the Oil Filter patrone and further filtered then all the way to the camshaft assembly as drawn in this sketch ... just follow the green arrows ... IMHO it is not good to mix those two functionally different oil circuits anywhere , since lubrication oil circuit is under pressure and uses filtered oil , on the other side is the cyl.head cooling oil circuit which work with very low oil presure and uses Unfiltered oil .

I would never connect those two separate oil circuits together, 1) for the simple reason that the engine head cooling oil circuit uses unfiltered oil , so that any dirt present in the oil can easily reach the rotating surfaces of the camshafts and can damage them significantly, 2) the oil pressures in those two separate systems are completely different, so any interaction between them can lead to problems, mainly problems with effective and good lubrication of the entire camshafts assembly, 3) if you want to achieve better and more efficient lubrication of the entire camshafts assembly, then the only way is to slightly widen the original left and right oil nozzles located in the engine block, since internal hole diameter of this two oil nozzles directly determine distributed filetred lubrication oil volume to entire camshafts assembly .

Long time ago I have the same problem with my 750 short stroke when I installed K&N RU2922 racing air filters , by changing standard #112,5 main jets with bigger #135 solved the problem , #37,5 pilot jets remained the same , all this on the standard Mikuni BST36SS carbs , btw , be very careful with that dedicated original K&N filter oil , that oil in contact with any rubber parts will have very negative effect causing rubber hardening .

First Pilots and not needles , leave needles in the central groove , check the spark plugs faces color than play with bigger or smaller size of the pilot jets , any way also check for those O-rings condition which are hidden behind any carbs intake rubber boots , if those O-rings are bad false vacuum leaking can occur causing nonlinear gas (acceleration) response and uneven operation on idle gas .

After constant ride at 3,5-4000 rpm remove and visually check the faces of the spark plugs , if the faces are black and greasy than your carbs runs rich , and opposite if the spark plugs faces are dry and almost grey to white than your carbs runs lean .

I don`t think so , since oil sub gallery is directly connected to the oil main gallery , you can clearly see that from the engine lubrication system chart from the original Suzuki GSXR-750 (FGH) service manual ,where oil sub gallery is supplied with pressurized oil which serve for cooling of the engine pistons via four plunger and associated nozzles ,so good oil sealing both for left and right side is very important , btw ,later GSXR models both 750 & 1100 crankcases are redesigned and simplified and don`t have that oil sub-gallery any more , but only oil main gallery.

Without that small brass plug oil sub-gallery perfect oil sealing will be just impossible , ignition engine cover altogether with associated gasket have nothing in common with oil sealing role of the oil sub-gallery .

On the each side of the lower engine block half is one brass plug , they have to be there and have to seat very tight and secured with some kind of the liquid bond , that`s from the reason because one brass plug close the oil main gallery end , and second one close the oil sub gallery end , both of these oil galleries are under full oil pressure so no oil leak is allowed , btw, to perfectly clean lower crankcase block half ( main oil gallery & oil sub-gallery) those two brass plugs and two plugs with thread must be removed mandatory !

Also I will check all spark plug caps , since sometime I have found that internal RFI protective resistor have been burned and destroyed , just replaced resistor with piece of solid copper wire of the same lenght and diameter as original resistor was solved the ignition problem , IMO & IME those internal RFI resistors actually is not needed if the spark plug is R-type , `R` stamp mean spark plug with internally integrated RFI resistor .

Thanks man ! Yes I have those J/K cams , same as nice race 4-2-1 exaust system altogether with K&N air filter .

I`m interested so please explain me , usually which GSXR parts is best to use to up the power ?

Year 1998 , question : Where this Bandit engine is power restricted to 72KW / 98 HP ? -on camshafts ? -on carbs ? -on CDI ? -on exaust system ? -on static compression ratio? -or somewhere else ?