750 katana bogs at 7 rpms

Use adjustable needles.there should be five slots start in middle and get bike running.then adjust according to if bike is running rich or lean.

When too much fuel is being supplied to the carburetors the engine is flooded. When you remove the spark plugs it allows the fuel to dissipate enough to allow the engine to run again. Drilling out the jets is not an accurate/preferred method for changing the jet size. Most of the time the jets end up being drilled too big. You can save money by just buying main jets. A jet kit usually will come with the slide needles made with a different taper from the stock needles. You may need to break down and buy a jet kit or a least replace the main jets with accurately sized main jets (not drilled out jets). In other words your main jets are just too big.

carb needs to be takin apart and cleaned in solvent--jet may need to be better ajusted-that takes expertize--chec plug wires and ign parts for wear

usually a light clicking could be your valve train and/or timing chain.

sounds to me like your carbs may need cleaning and or a rebuild, i had a 750 katana that would do that as well, didnt want to idle when cold, then too fast when warm/hot, gave my carbs a good cleaning and it cleared up, the jets can get plugged really easily, could also be bad gas, any contamination and or particles can cause problems, especially if the bike sits without running for too long, hope this helps =)

I think your right they are full of bull, I think they rejetted it to a larger jet which makes it stall out or studders at lower rpms. I would make them put it on a machine and test it for proper mixer for the type of rideing that you do.

sounds like its starving a bit , try adjusting the fuel air mix screw,  Take air filter out and give it a good clean first before any adjustments ok?

7k is where the main jets kick in in the carbs i would guess they are plugged somehow here is a free service manual download also check out www.katriders.com and type carbs 101 in tthe search box http://rtcdesign.com/gsx600f_manual/GSX600F.pdf

• First I would go get stock plugs from the dealer. Plugs with incorrect heat range can cause overheating.
• Drain the oil and replace the oil filter. Refill the crankcase with fresh oil. Also be sure exhaust gasses are getting through the exhaust pipes okay
• Check the spark timing. and clean or replace the air filter.

Your mechanic probably installed carb rebuild kits in each carb. This is good but the correct main jets may not have come in the generic kits he bought. Too small a main jet can cause overheating. Pull the float bowl of whichever carb is easiest to get to. Remove the main jet and look to see what size it is. There will be a number i.e. 3.0 stamped on the jet. Call your dealers parts department and ask what size main jet is stock. The smaller the number, the smaller the jet. Re-jet the carbs if needed.

I hope you can rate this solution as a "FixYa". Thanks!