1974 KZ400 - Long strange trip

I have been working on a 1974 KZ400 for about 10 years.  At first I didn't know much about motorcycles and had a shop work on the bike.  The bike war burning oil when I got it.  Famous last words - the guy said that the smoke was not a problem!  Spent several thousand on a guy who couldn't do the top end - tried three times and it still leaked.  I then took it to another guy who said he was an engine expert.  Got it back and noticed that he hadn't put the cam chain tensioner back on - oil all over the driveway.  The bike burned oil and was a mess.  He refused to repair it and ripped me off for the work.  I finally found a guy who knew what he was doing and he finished the top end  However, he could not get the bike to rum properly.  By this time I started to know what I was doing and had cleaned and installed several carbs on other bikes.  I purchased a set of aftermarket Keihin VM32 carbs and converted the bike into a cafe racer.  Finally, last summer, after about 9 years I finally got the bike to run properly.  However, the right pod filter was too large and caused the carb to sit on an angle and leaked fuel.  I purchased a set of UNI offset filters last year, installed them but the bike ran horribly.  Decided to go back to K&N style filters offset - and they fit!  Started the bike yesterday and it ran but only with the filters off.  I will reduce the size of the pilot jets from 25 to 20 today as recommended on this form and try again.  Hopefully this summer the bike will be on the road! 

Pic of your plugs?
Steve
 

Welcome, let's see some pic's of your progress (unfortunately the world is full of "experts") 

Finding an honest mechanic who really knows these old air cooled, carbureted engines is a bit like finding a leprechaun riding a unicorn pulling a cartload of gold.

Owning one means learning how to do all of the maintenance and most common repairs. Fortunately, there are a goodly number of enthusiasts here, many with extensive experience, ready to help.