TOPIC:

I imagine that for the cam timing to have changed, the cam chain would have to be so far from being at the correct ‘tension’  that you would have had audible warning that something was amiss in that department. Was the engine sounding rattly?


 

Seeing as we're grasping at straws with this topic,  I'll toss this into the fire ( no pun intended) :Are you certain you are not experiencing "cross-firing" of a spark-plug lead(s) ?  
This would explain the elusive but apparent randomness of the erratic starting and running..

Regarding the burning of the bike.  I'll suggest using my go-to fluid...... Lacquer Thinner.
You'll  get the satisfaction of lighting-up the bike   but it will flash-off quickly so at that moment when you think "WTF" have I just done .....the flames should already be out 
 

On the topic of sparkplug leads cross firing: You can sometimes actually hear the "crack" as the spark jumps.  Turn off the shop lights and you may even see the arcing.  No luck ?  "Ground".one hand to the frame and touch each lead one at a time with the other.  If this is the case.........You'll quickly discover "the jumper" 

I'm still concerned that this could be Ignition Timing related.   

biltonjim wrote:

I imagine that for the cam timing to have changed, the cam chain would have to be so far from being at the correct ‘tension’  that you would have had audible warning that something was amiss in that department. Was the engine sounding rattly?

The motor has always been a little noisy on initial start up but quickly quietens down after 15-20 seconds. It’s not horrendously noisy but louder than I would like. The tensioner has been modified with the 6mm bolt and lock nut and I’ve adjusted it by feel. I plan to renew the chain and tensioner at some point. 


 

scotch wrote:

On the topic of sparkplug leads cross firing: You can sometimes actually hear the "crack" as the spark jumps.  Turn off the shop lights and you may even see the arcing.  No luck ?  "Ground".one hand to the frame and touch each lead one at a time with the other.  If this is the case.........You'll quickly discover "the jumper" 

I'm still concerned that this could be Ignition Timing related.   

I’ve not noticed any arcing or heard an audible crack so I will  try your “suicide” check next time I fire it up

 

"May the Force be with you !"