Bike has a ton of trouble starting

I own a ‘79 kz750. First, the electrical start always had some trouble getting the bike started even when the starter motor did turn over, but now it won’t turn over any more (and indicator lights go dim). I guess that probably means I need to charge the battery. But since the starter motor stopped turning over I’ve been using the kick starter, which also has a hard time getting it started. Sometimes the engine will turn over once then die. Spark plugs are new and properly spaced. What can I fix so that I don’t have to put in a 30 minute workout every time I want to start my bike? 

If the battery is bad, it will not start even with the kicker.
Have you checked to be sure the lash on each valve is within the proper range?
Is the engine harder to start cold than it is hot?
Are the spark plug leads hooked up to the proper spark plugs?
When the engine is not warmed up, do you lift the enrichener lever and NOT turn the throttle when trying to start?
Do you know for certain if the carbs are spotlessly clean inside and correctly adjusted?
Does the bike have the factory air box in place with a clean filter in it?

The battery is new, and was charged when I put it in last week but I may need to recharge it.

I have not checked to see if the lash on each valve is in the proper range. I’ll consult the repair manual as to what that actually means (I’m very new to this).

The engine is harder to start cold than it is hot.

The spark plugs are hooked up to the proper leads. 

When the engine is cold, I do lift the enricher and I have NOT been pulling the throttle. Sometimes it seems to have a harder time starting with the enricher. 

I personally have not cleaned the carbs, I’ll do that.

The bike doesn’t have a factory air box. The image shows what it has in place, I was not the one who made the change. 


 

Checking the valve lash is an important part of the regular maintenance.
When using individual filters, the jets in the carburetors need to be swapped for larger ones, as the filters make the mixture very lean. It would be worthwhile to see what jets are in them. With everything properly tuned up, it should be fairly easy to kick start. 
By the way, what happened to the electric starter?
Do you have a factory service manual for this bike?

P.S. I apologize for the spark plug lead question, I was thinking of a four cylinder 750. On the twins, it does not matter.

Thanks for your help. I do have a service manual for this bike that I found online. With the electric starter, originally the starter motor would turn but engine wouldn’t start. After several times trying I think the battery is somewhat discharged so it’s charging now. I think I may need to replace the starter motor clutch or something, I’ll have to open it up and take a look.