lack of power

78 kz650 c2. feels like it only has half the power it had last week. all cylinders firing. engine feels really hot and cylinder 1 heats up alot faster than cylinder 4. doesn't have any leak in the boots or anything. everything is stock. what do u guys think ?

Time for a tune-up? Ed

it has new plugs, air filter, oil filter& oil, points and condenser, carbs cleaned.

are you suggesting a more in depth tuneup such as valve clearance check and carb sync?

If a bike lose a lot of power almost overnight, something has gone wrong. Meaning more than the usual wear of points or valve clearances, which will be very gradual.

Personally, I would start with the ignition timing and stability. Hook up a strobe and check that timing is correct and that the advancer operates smoothly; it can become stuck or partially stuck and this will definitely be noticed in the power department. Also, if the light flickers on one or more of the cylinders, you have some issues with spark plugs or HT leads/caps or ignition coils or points/condensers. Check points for pitting.

If ignition is sound move over to the fuel supply. Could it be contaminated with water? Or something restricting flow, like rust or a partially clogged petcock or tank vent? Drain each carb into a clean container and measure the amount and also look for foreign particles.

Then a compression check, if fuel looks good, too. If you have fuel in the correct amount, a strong spark when needed and compression, you should have a strong running engine. One of these 3 isn't performing as they should on your machine.