There was soot and oil and hard bits of carbon all over both valves in & out (both sides), piston, rings, heads and air in take and air filter. Everything was coated.
It took me a while to suss out what had happened.
When kick-starting the bike and not giving it enough of a kick, some times the pistons would be pushed back down the cylinder due to the high compression. The flywheel now running in the wrong direction, and the engine would start running backwards.
The air was being suck from the exhaust and all the crap in it was sucked in to the engine and out of the air filter.
I am now half way through a top end re build.
This ends all thoughts of taking the starter motor off my bike to save weight.
I'm now looking to fit a bigger battery to cope with the power hungry starter motor.
By the way, I have found that these starter motors have a direct short to earth if you over tighten the live cable nut, even by a slight amount.
I have tested two starters, both had this problem. Almost a year after the last electrical catastrophe (Hamm 2012) I have sussed out that these starters are well dodgy.
A tempory cure is to fit one thin nut 3/4 the way down the thread, then fit the cable and nut.
In the owners manual it states the live output from the reg rec goes to the starter, then on to the battery (this is why my battery didn't charge and eventually died at Hamm last year). I shall be changing this so the charging cable goes direct to the battery live, so I can un hook the starter cable if need be.