Motorcycle Repair: Kerker exhaust, 1980 kawasaki kz1000, fuel air mixture

Question
I just bought a 1980 Kawasaki kz1000. The person I bought it from put on a Kerker exhaust and through away the original pipes. So the bike went from 2 pipes to 1. Since then the bike hasn't run. I looked up Kerker exhaust and it said there would have to be fuel air mixture adjustments, but it didn't say what to do. The bike ran fine before. Any advice would be greatly appreciated.
Thank you!

Answer
Hi Dennis,

Some tuning may be necessary to correct the air-fuel mixtures, but the engine should start and run after installing the Kerker pipe.

I (we're) not getting the full story. I suspect other problems exist. Do you know any history of repairs to this Kaw? What was done to carbs after pipe was installed? Was it stored awhile either before or after you took possession?

I'll need you to describe each spark plug to me. Remember which cylinder the plugs were removed from. Cylinders are numbered left to right 1-2-3-4, when sitting on the MC.

Include your email address as requested. I return tech files via email. We'll go from there.

Respectfully,
Mark Shively