Backfiring 82 KZ1100. Won't start.

Kz1100 a2 shaft 1982.

I did a cafe racer out of it all winter. I'm done, no start.

- took engine out, adjusted valves, all within specs
- simplified and rewire everything (no more lockout switch for example)... I followed instructions on www.bikeexif.com/motorcycle-wiring
- bike is turning, had to change starter clutch, sprocket and starter
- I have spark on all 4 spark plugs
- fuel in carbs
- checked compression: #1: 155psi #2 150 #3 150 #4 155

Everything seems in specs, while its turning, the bike will backfire, with flames coming out the tail pipes.

I'm completely out of ideas, please help

Spark plug wires hooked up wrong? One coil fires cylinders 1 an4, the other one fires 2 and 3.

Coils wired backwards? That is, is the left coil getting the right coil signal, and vice versa?

Tks for the reply, I'm currently finishing cleaning my carbs, but I went to check the coils wiring. Does it make a difference if I switch blue and red wires on one left side coil? I'll be able to test in about 1/2 hours after I reinstall carbs

So I cleaned my carbs, checked ignition wiring, still nothing... Just cranks and cranks and 'pow' pow exhaust and fumes coming out my air filter pods.

Any more help would be apreciated

New update, checked timing and valve clearance, everything is dead on. Still no start. I can see flames and fire in my pod filters when I crank and it pops

new update: I installed some cheap emgo pod filters while putting the bike togheter, now I found a thread about the inside of the pod blocking all the carbs air ports. now that they are off, my battery is totally drained and the engine flooded.. so i can't test without filters until tomorrow.

question is, could blocking all the vent ports on the carbs create a 'no start' issue????

Your advancer isn't 180 out is it?

If it was, my wires would be facing up, no?

No he's talking about the advancer behind the points plate ...... did you remove it to clean and grease it ? If not it won't be it.

I recall removing the ignition plate for better seeing the timing marks when i adjusted the valves clearance. Bu t I dont recall messing around with the advancer itself...

but now, after looking at this thread, i found something... since i started messing with the bike, I've been rotating the engine using the 12mm bolt, not the 17mm.

maybe something is off, I'll take a look tonight.

havent been easy since the bike was put togheter,
1. I burnt the starter, replaced with a cb900 starter
2. Burnt the starter clutch, replace springs and other round metal things, didn't worked, had to find a new starter clutch and sproket (mine had scratches).
3. pulling the magneto rotor to replace starter clutch, I droped it on the floor, the magnet inside broke.
4. So I finally bought a KZ1000 for 350$, not possible to put on the road (previous owner didn't pay tickets), so now I have lots of parts.

everthing replaced, not I can't start the bike. can't wait to check the advancer tonight.


thanks

HELP. Decided to start a new post because of the progress. KZ1100 a2 shaft. NO START. Backfires when cranking.

After checking :
- fuel in carbs
- advancer timing mechanic is ok(not 180 degree impossible on my bike)
- compression is good on all cylinders)
- spark on all plugs
- engine timing is dead on
- valve clearance is dead on
- I redid all the wiring, I must of checked 10 times each single wire
- spark plugs leads are connected the right way
- cleaned my carbs yesterday

NOW, I noticed that when I'm cranking without plug #2, it doesn't backfires / pops

If #2 is plug, cranking without air filters, carb #2 is popping, shooting out fuel

Where can I look now?

Switch the two wires coming from the points.
Steve