Greetings and condolences Andwew,
Like everyone else, I am glad that you were not physically hurt.
The emotional trauma must have been very difficult to deal with. Being forced to stand by as a beloved ride burns and unable to do anything must have been heartbreaking.
I understand that this would leave one searching for answers as to a cause.
I am no fire investigation expert, but will hazard a guess based from research and experience of working on mine and friends K's.
True these bikes are getting old, yet similar things have happened in the past when age wasn't a real factor. From memory, previous causes for K fires were:
1) Electrical. An electrical short can cause a small fire that quickly burns through the fuel lines. This seems to have been the most common cause of fires in these older K's, at least from what I've read.
2)Faulty quick dis-connect fuel line hardware.
3) The fuel pressure regulators location on most of the K's I've seen is a large contributing factor to the hot tank syndrome(where the fuel gets very hot when tank is below 1/2.)
The regulator sits in a very hot area. This heat can cause the fuel lines to deteriorate more quickly at the regulator.
Visually checking these is impossible from the left side. You can see them from the right side but they can look perfect until you touch or pull them to check. This is why I relocated mine.
These would be my 3 best guesses. Notice that all three are things that, most likely, you wouldn't be able to see any problem through visual inspection. Point I'm making is, don't beat yourself up.
Hope this helps,
Freelancer
P.S. Ebay has some very good deals on K75's right now.
