Gpz750 Racer (Wiseco 810) Dyna 2000 ignition issues

Hi, just completed a cafe racer with full engine rebuild and fully customized 1983 GPz750 and having issues with the ignition. Bike runs fine and starts perfect, I can ride it up to 50km without a problem and quite fast, but it then start running on 3 cylinders until it just dies. It then can be restared but still running on 3 and dies properly a few minutes later. Trouble is is starts running perfectly again if I try to restart it 5-10 minutes later... please help if you know what this can be ?

Bike has : motogadget m unit fuse box, full Dyna 2000 ignition system (plate ignitor coils and leads) brand new starter relay new headlight new indicators new acewell speedo/tachi, fully new and custom wiring harness (soldered and heat shrunk), new regulator from ricks’s motorsport, the engine has been fully reconned with a Wiseco 810cc piston kit, new primary secondary chains, new valves and springs, etc etc

The tacho is still well wired but started acting up recently (reading comes from ignitor) - I have contacted dyna and they said its most likely a wiring issue which i dont believe as it runs so well and then sorts itself out withour touching anything ! Like a gremlin living inside my bike

Bike has 150km since the build was complete and broke down maybe 3 times in that period. The good part is I don’t get stranded but obviously this is far from ideal

Let me know your thoughts !

Does sound like an electrical component , coil etc breaking down under load BUT first make sure it isn't something daft like a blocked fuel tank vent as this will produce the same symptoms.

I agree with zed... did you line your fuel tank? That's an easy way to block off your tank vent if you're not paying attention. I speak from personal experience

Could the battery be discharging? See if it's 14+v with engine running.

Is it always the same piston who dies?

Thanks for the help gents - after rewiring the stock ignition that I kept, same problem happened ... turns out it is air lock in the tank ! As it died on me I opened the cap and a lot of fuel could be seen rushing through the filter ... #fml !!! ordered a stock tank cap from partszilla and its now sorted and its a sweet ride ! Hope this helps others down the line !!

Final Dyno figure for a free flowing exhaust, pod filters, Wiseco 810cc kit .... drumroll ... 77.89 Rear Wheel Horses, about 90 bhp I recon.

If you add a good set of either Web Cams, or Megacycle Cams, both degreed properly, you should see a good increase in HP and Tq. I got +11 hp and +4 tq.at the rear wheel by doing this to my GPz550 with 615 Kit by adding Megacycle Cams.