Needing to replace the whole key switch on a 86 750 vulcan kawaski need the cheapest

sounds like carb, is airfilter set up ok, it can act as an air restrictor to match the jetting

TO ALL VN1500 OWNERS....This once happen to me,
I went to the garage to start the bike "Nothing ""The first thing is the lights are bright but no turning over,Next you think the solenoid is kaput but the answer was very simple and the fix takes 30 seconds..
Do not take the bike to bits looking for other problems and look at the clutch leaver and you will see some wires going into a plastic shroud going into the switch in the clutch leaver, Make sure this has not popped out if its connection as it some times may do after a few years due to constant turning on the handlebars,
When this is not connected you will have a bike that will not fire up but comes alive and you will hear a clicking noise but this is from the engine carb area and every function of the bike will work but it will not turn over, Worth looking at and saves sixteen quid for a starter unit you never needed.

You need a new Needle Jet and maybe clean up the seat

You can lightly tap on the side of the bowl to dislodge it. If this doesn't work, you need to remove the bowl. (Or the carb needs to be removed to get at the bowl.)

Your ignition switch is bad if you have to giggle it to get it to make good contact.

keep pressing the starter and find out were the click is comeing from,, then change the starter solenoid, it sounds like this is at fault

depends on where you loive [weather extemes]
below zero & very hot summers i would use 0/40
average temps 10/40 wieght oil
dont mix brands stay with one always & get a good synthetic oil
no cheap stuff !
as its a good insurance policy for your investment [bike]
Cheers rob

if you plan to modify your exhaust system you will have to rejet your carbs to compansate. kits are availableat most aftermarket shops.