1976 KZ400 Engine problem

Now, I got the old girl up and running and riding pretty good. Now, this morning I was going to take her up town to get something to eat and went to start it. Went to start, put the choke on, and cranked with the electrical start and heard a click. So, I thought let's try with the kick start, which does work. Tried to kick start it and smoke started to come out of the right carb. Took the air filter off, and looked to see if the carb was stuck, no it's free, took the right exhaust off, and saw the exhaust valve is closed. So, I figured I'd try to start it with the exhaust off and it's a HARD rebound and no start, smoke (exhaust) out of carb. So, I figured I'd ask you guys on your thoughts on this. My new weekend project is to take the engine out of the motorcycle and look into further, but if you guys have a better idea or thoughts please let me know. Could it be the valve being stuck or broken, or something else. The engine cranks but does not start.

I would check the battery first. Put your meter on the battery posts and take a reading. A healthy, fully charged battery should read 13.2v. Next turn the ignition key on and check the reading. Then press the starter button and note the reading. If on the last test it drops below 11v, a new battery is in your future.
Do not take tha engine out or apart. Put the exhaust back on. You will need a new gasket for the one you removed. There are several possible causes that do not require a teardown.

What would be next after the battery, haven't been able to test battery yet, but it's a new battery and figured since I'm out can I pick up anything.

New batteries can be bad.
Check both ends of both battery cables to be sure they have clean, tight connections.
Check the fuses with your multi meter. Those old glass fuses can look good, but be disconnected inside near the end where you cannot see the break.
I suspect you have an electrical problem that is preventing your starter and ignition system from working. There may be other problems like no valve lash that are adding to your misery. Have you checked the valve clearances lately?

You said you pulled the air filter off to look in the carburetor. Does that mean you have individual, aka pod, filters? If so, are the carberators properly jetted for them?
Does the bike have the factory exhaust in place?

Check the oil level. Is it higher than the last time you checked? Remove the oil fill cap and sniff the crankcase. Does it smell like gasoline? If one or both of the float valves are not sealing a cylinder can fill up with gasoline and hydro lock. Gasoline will also leak past the rings into the crankcase. If that has happened, DO NOT TRY TO START THE ENGINE.
If this has happened, you will need to remove and properly clean the carbs, and reassemble them with new gaskets and orings. The engine oil and filter will also need to be replaced.

The carbs are brand new from a reputable motorcycle shop. They are Mikuni 30 carbs, they are jetted to the motorcycle, took the motorcycle to their shop so they could do it. This morning I did find a few things out, main fuse blew, replaced and same condition, apparently one of the, I want to call them a cam shaft port plugs must of been brittle or overtightened because when I went to remove it the head just snapped off, but thankfully was able to to remove it without damage to the motor. How would I check the valve clearance?

Here is a link to a downloadable, searchable factory service manual. It shows the procedure. Please do not proceed without carefully reading that section of the manual first. It is not a complicated procedure, but it must be carefully followed or you may cause damage to the engine.

www.kzrider.com/modules/ServiceManuals/7...chablefullmanual.pdf

You need to find out why that fuse blew. There is a problem in the electrical system that needs to be fixed.

Did you check the oil? Yes, I understand at the carbs are new, but that does not mean that some dirt or rust from the fuel tank did not get into them and cause a problem.

Ok, removed spark plugs and 0 fluid in the cylinder, piston and valves move freely and properly, plenty of compression. Removed and cleaned carbs, some dirt did get through the fuel filters. Changed oil and oil filter. I'm going to check the coil, it is an older coil and going to see if maybe the coil shorted out.

Last thing before I'm done for today. I removed the camshaft cover to further inspect the valves, camshaft, timing, and chain. Everything looks to be in good condition, no worn spots on crankshaft, no broken or worn valves, chain is nice and snug, and timing in on spot. Put everything together and just waiting to find a valve inspection port bolt. Bought new spark plugs, new battery, and coil tests good. Regapped points and didn't really find a cause for the blown fuse, but will look further into it tomorrow. Fuse holder was rusty, cleaned holder and installed a new fuse. But still same condition, push starter button and it just spins, use kick start, and counted this time, by the fourth kick wants to turn over, but blows fuel/air back out through carb.

Is the thing that broke in this picture?

www.partzilla.com/catalog/kawasaki/motor...covers-76-77-kz400-d