Backfiring 82 KZ1100. Won't start.

eric951turbo wrote: - advancer timing mechanic is ok(not 180 degree impossible on my bike)

Easily possible, when disassembled for maintenance. Once the pickup-plate is removed (three screws), spread the weights and slide the magnet sleeve out to rotate 180 degrees.
I don't remember if my engine backfired or popped :laugh:, but did not start til done...

I meant switching the two wires at the coils.
Steve

It's alive. Happy and pissed off at the same time. Black and green leads on coils.... My kawa book is full of crap. While looking for this stupid problem, I manage to brake a bolt in the head (checking valve clearance), stripping alternator bolts, and now my new starter clutch is already grinding because of all the cranking. Hopefully this bike will give me love in the future.

...If the black and green wires were swapped, it could be the rotor was flipped 180 in the past.

On the big motors (900/1000/1100):
The rear black/blue pickup detects 1-4. This triggers the module to fire the black wire to the left coil which is for 1-4.
The front yellow/red pickup detects 2-3. This triggers the module to fire the green wire to the right coil which is for 2-3.
When 1&4 are at TDC, the rotor should point toward the rear black/blue pickup.

(The smaller fours have the coils swapped left and right.)

thanks Loud, I'll check if everything is intact tonight.

It started really late last night in my garage, I couldn't sleep, had the idea of swapping the green and black wires, went in the garage wearing my boxer short lol... broooooooom started right away... but there was so much fuel in my carbs that it spitted, and i was charging the battery and touched the positive at the same time... you can guess what.... FIRE!!! near the battery... i was able to put it out quickly. you can imagine the scenario.

Dodged a bullet on that one. Almost did a Richard Prier. At least he could joke about it.
Steve

So I got home from work all exited to start the bike. Ok, it starts, but runs like if I put 1000 bags of popcorn in the microwave.

I cleaned all the plugs, put them back, same thing. Reminder that I installed pods and new custom mufflers.

Haven't changed pilot and main yet, ordered them from z1e today.

The green wire is reverse with the black wire, so I guess the previous owner swapped something .

If I don't lift throttle, it will stay running for about 30 seconds without popping or backfiring, but then it dies and unable to start for another 30 minutes.

Other than carb jets, could the problem be something else?

Try switching the wires coming from the points or pick ups.
I deleted your last topic per your request. It can be renewed if needed.
Steve

Do you mean switching green and black intbeen pickup and ic ignitor???

I did rewire the the bike, but I didn't touch the wires from pickup to ic ignitor.

right now, if the green and black wires are connected correctly (green right coil, black left coil).... Bike doesn't starts, only pops.

If I switch black and green, bike starts, runs smooth on idle, pops very hard and baxkfires just by lifting a bit the throttle, then engine dies.

Brand new intake rubbers, no leaks.

I did notice that it looks like it's popping (flames) true #2 and 3 carbs. But I might be mistaken.

About the mechanical advancer, I looked at it again and I seropiously don't understand how you can rotate it 180 degrees.

First, you got a pin, and second, the mark needs to be align with the mark on the plate. And yes I checked, at tdc, it's pointing at the correct wires, I don't understand how you can rotate 180 degrees and be align?

Have you checked the valve adjustments?
Steve

Yes I did, all in specs, between .05 and .15mm

The bike was popping a little on idle when I bought it last fall, po told me probably carbs. I got home and cleaned them, no difference. Then I dissemble the bike for painting and frame modifications. Adjusted valves while engine was off, 3 valves where too tight.

Also, did a compression test yesterday: #1: 155 # 2 150 #3 150 #4 155