Couple Questions?

Im kinda a newbie to these bikes, I inherited a 79' KZ650 B-3 from my uncle, it had been sitting for a few years, I know my way around some small engines so I began by taking the carbs down and cleaning them, changed the filter to pods K&N, changed the plugs and changed the fluids. He had replaced the points with the Dyna S ignition and the coils with accel super coils.

I want to install a 4-1 exhaust and I am wondering what I should jet my carbs over to and do I have to buy a kit or can I order the individual jets from the dealer?

Also is there an easy way to check the timming i dont know if the timming is accurate it doesn't seem to run correctly or it could be a lean condition because of the pods and things Idk he every jetted the carbs over.

Can you use motor oil or do you need special oil for bikes?

If the bike was sitting a few years don't run it until you change the oil!! God only know what the goop that in it now will do to the bearing/rings/ and such. Look elsewhere on this site (do a search) and you'll find 100 "what's the best oil to use" discussions. Do you have the Kawasaki factory service manual? If not, you should relax on working on the bike (especially timing and such) until you get one. Get the one for your specific year/model from eBay. If it was mine, I'd put the stock airbox etc. back on it and get it running right (after changing oil) before I started modifying stuff. Otherwise you won't have a clue as to what's causing it to run poorly. In other words, establish a good running stock baseline from which to work instead of removing air filter, changing timing, changing exhaust etc. and then not knowing the effect of each change on the other. That way when you make a change (perhaps for the worse i.e. as in pods) you will know the exact cause of the performance problem and can work to correct it (i.e. as in rejetting). Then save all the stock stuff so you can put it back on if you get frustrated after trying to find the magic combination of mods or if you decide to sell. And for Pete's sake, be sure to use the appropriate torque wrenches. Otherwise be prepared to do another search on this site for "timeserts and helicoils." Ed