Troubles in the engine/adjustment part..

With this custom ignition, are you using the stock coils?  If not, do you know what coils you have?

Since it only has one pickup instead the more typical two pickups, it seems like this ignition must fire all coils at the same time.  This would end up firing a single coil twice as often as would normally be the case.  One potential issue with this setup is that the coil may not have time to fully charge at higher RPM, since the dwell time is cut in half.  If that's the case, the amount of energy in the spark will fall off at higher RPM.

This is basically the same as operating the coil at double the engine speed than it was designed for.  I suspect that most KZ coils would not work well at an engine speed of 17,000 RPM (8500 x 2).  

It has stock coils indeed, how I bought the bike. 

Think of it this way. If there's spark at the bottom of the intake stroke it will burn the gas before it has a chance to compress rendering it useless. Sure it fires 180* apart but I don't see how it can work without firing the other cylinders on time.
Steve

It has one pick up but two points on the nut which triggers it, so it fires every 180* 
it divides the sparks over two coils, so I don't see how it could fire at bottom centre. But again, I know nothing, but try to learn everything

Since you didn't design your custom ignition, and don't really know exactly how it works, I think you'll have much better luck and an easier time if you replace it with something more standard.

I recommend the Dynatek Dyna S.  It's designed to work with the stock coils and the stock mechanical advancer.  They've been around for years.  Many people here use them and they are generally very reliable and "just work". 

www.denniskirk.com/dynatek/s-ignition-ds2-1.p20273.prd

When cylinder one is tdc and firing, cylinder two is at the bottom of its intake stroke. If the plug in number two fires at that point, the fuel would be burned up before he piston got to tdc, so there would be nothing left to push the piston down. At the same time, number 3 would also be at bdc getting ready to start its exhaust stroke. Since there was no spark at tdc, the spark would ignight the fuel charge as it was going out of the exhaust valve. Number four would be at tdc at the same time as number one, but four would be starting its intake stroke, so a spark at this moment would ignite the charge with the intake valve open, backfiring through the carburetor. And on and on…..

I just now found out, that cilinder 3+4 don't fire. Both exhaust pipes stay cold when running. Maybe one of you guys, with your knowledge, can tell me if it is possible (with this weird ignition) that it's because of perhaps a faulty ignition coil, or if it is a fuel problem. 

Live to hear your ideas 

I don’t think there is any way to answer that question without knowing a lot more about the system. In a stock system, one coil fires cylinders 1 & 4, while the other fires 2 & 3.

 

wrote:

It has one pick up but two points on the nut which triggers it, so it fires every 180* 
it divides the sparks over two coils, so I don't see how it could fire at bottom centre. But again, I know nothing, but try to learn everything

When two pistons are at the top of their stroke, one is firing, the other exhausting. At the same moment, the other two are at the bottom, one just finishing intake and the other just finished firing.  Then 180 degrees later, the opposite is true. If all four plugs fire at the same time every 180 degrees, two cylinders will always be at the bottom.
It would be interesting to see the whole system to see what is going on.
Where do the two wires coming from the trigger go?

As shown, there is a single magnetic sensor, with a (I'll call it a weird nut) on the crank with two points, 180* apart, and the original mechanical spark advance.. I'll have to check where the wires are going, but I'm more and more looking for a proper ignition, and I'd love to have a ignition who fires and advances digitally, on a set curve.

I personally think it's impossible to be a carb, or fuel thing. The carbs do get fuel, and the fuel lines show tiny bubble's when the engine is running. So it is taking on fuel  when running, and not when engine is turned off..

Have you got spark at 3+4 cyls?

If you have spark at those cylinders that are not working it's looking more like a large vac leak or blocked passages in your recently cleaned carbs.

It appears your problems only started soon after oil leak repairs and carby cleaning, It has got to be related to these recent operations. I don't believe in coincidences.

 Nose burn=Rich   Eyes burn=Lean.

Had a few sec today to pull the tank, ignition coils and plugs. Tried a spark test again, and still no spark on 3+4 while 1+2 are firing.. Coil one is connected to cilinder 1+4 and the second coil to 2+3. All plugs are black, and a bit greasy, are only 50km's old. Gas is coming in. Had the engine running on 2 cilinders and on full throttle you can see gas going in al 4 cilinders. I am stuck here