i almost let it burn

so i finally got my head back on for the second time (the first time i had it completely bolted down and a dow pin fell inside the cylinder:( ) i get it all bolted down again set my cams in get it in time and i put the cam caps on and start to tighten down the bolts they strip....1 right after another all 8 bolts for the exhaust cam caps were striped so after taping all of the holes back out the bolts will not fit through the cam caps so i drill them out...after i get that all done i go to put in the bearings and im missing 1 i completely searched my entire garage and i cant find it so i look through some of the spare parts i find another one and put it in...so i start to bolt down the cam caps again and part of the head cracks :ohmy: after cleaning it and fixing it i got the bolt back in...got to put my valve cover on and it does not fit because of the bigger bolts i put in :laugh: so i pull out the dremel and take off some of the inside of the valve cover get it bolted on...get the carbs on put all the ignition back on check all of my plugs to make sure i have spark....i dont...checked all connections and i cant find anything wrong...i decided to hook up a battery and my headlight and everything comes on so i check to see if i have spark again now i do across all for cylinders and after that i decide to see if my electric start works....it dosent :side:.....so i just spray some starting fluid in the carbs and kick it over and all i get is back fires out of the carbs...checked to see if i had the plug wires on right and i did... after kicking it over some more and burning all the hair off the sides of my legs and putting out a big fire that somehow started on top of the head i decide to call it quits for the day so i come inside for a little while....i cant sleep so i go back out to the garage and try starting it again after getting more backfires from cylinders 1&4 and nothing out of 2&3 i kick it over again and a huge fire starts right underneath me....if i had been outside i would have just kicked it over and watched it burn...but i was not going to burn down my garage so after getting the fire out and making sure all the wiring was ok...i quit and here i am
i really dont know what to do

Make sure the plugs are wired in the right order, other than that, wait for one of the Guru's to chime in in the morning. I understand the temptation to let the thing burn, I almost did to my KZ, but it will only be something you regret. If it is getting to you that badly, put it in the back of the garage, and find something else to tinker with for a few days then go back at it with some friends or some riders from this forum.

yea no burning lol. it sounds like an ignition thing. i would check your spark plug wires to see if it's arcing from the wire to the head. check your compression just for insurance or piece of mind that you set your cams correctly. Just take your time, make a list of everything every one writes on here and check each one and cross them off as you go. These are fun bikes and incredibly tinker friendly. Good luck

Remove rotor (points cam) from timing advancer.
Rotate rotor 180 degrees.
Reinstall rotor.

That ought to fix that problem.

Elliot's method of fixing the problem will likely work but I HATE seeing the green wire to to the 1/4 coil hehe...

It is likely if you are getting backfiring, that the wires coming off your point or IC igniter or Dyna S (you didn't mention bike type nor ignition type) are on the wrong coils. By flipping the rotor over, you can have the points or pickup coils or Dyna S fire 180 out from where it had been firing and the problem will be fixed except for when someone else goes to work on the bike and will get all confused.

Here is what you do:
1. put your bike year/model in your signature by going into your profile and editing it. If you want, put in your location. If I am near, I will jump onto my shafty and ride over and help you out. If not, maybe someone else could

2. REMOVE POINTS COVER
3. Look at your a. points b. pickup coils c. Dyna S ignitiion
4. the one on the LEFT is the one that should fire the 1&4 plugs and the one on the right should fire the 2&3
5. Remove your spark plugs and turn the engine over to TDC for 1 & 4 cylinders; that is, the #4 piston comes up to the top of its stroke and you can feel it if you stick your finger in the plug hole. Use the 17mm nut on the crank end to turn the engine over.
6. Take off the rotor Mr. Elliot referred to and look at it carefully. There is a small indentation that is round and slightly smaller than a pencil eraser. That indentation is a magnet. When the magnet passes by your a. points b. IC Igniter pickup coils c. Dyna S pickup, the plugs adjacent will fire. If you are at TDC for 1 & 4 the magnet should be at about the 9 o'clock position; in other words it will be to the LEFT and BELOW the timing mark on the engine case.
7. Yippee! You have the rotor on right. Now look at the wire coming off your 1 & 4 a. points (the points on the left) b. your IC Igniter pickup coil (the one on the left) c. left Dyna S pickup. You will have a BLACK wire coming off either selection a. or b. and I THINK a white wire off a Dyna S but it should have a BLACK plastic ring up where it connections to your coil. THIS WIRE IS THE 1 & 4 plug wire. It should connect to the RIGHT coil as you sit on the bike. This wire makes that coil the 1 & 4 coil so the spark plug wires that come off this coil should go to the 1 & 4 spark plugs.
8. Do the same wire chasing for the RIGHT a. points b. IC Igniter pickup coils c. DYNA S pickup. The wire or plastic ring will be GREEN and this wire should hook to the 2 & 3 coil which will have plug leads going to the, (you guessed it) 2 & 3 spark plugs.

While you MIGHT have some other problem, this issue is mostly ignition related.

it is a 1974 z1 900
it has a TAC electronic ignition