Don't do as I do! Do as I say!

There I was, contemplating the CEF Speed contest and thinking "Which engine would I use?"
 
So I thought - Ron is contemplating a Space Hopper and going retro - therefore, I am older than he is and so I will go more retro.
 
Thermal Hopper it is then!
 
I dug out my "Bitza" - Bits of this and bits of that - and decided to run it in.
 
After careful mounting, it started first flick ( well lucky methinks!) and I let it burble steadily - 20% nitro, 5 x 4 round tip Cox propeller, 14k - three tanks, cooling off in between.
 
Then moved to a 5 1/4 x 4 Top Flite Nylon two more tanks - steady 15.1K.
 
Now for RULE 1 - DON'T USE OLD NYLON PROPELLERS
 
and       RULE 2 - DON'T USE UNBALANCED PROPELLERS
I then moved onwards
 
5 x 4 Flat tip Cox prop - 15.7K
5 x 3 Saftey tip Cox prop - 16.2K
 
Then - 4 3/4 x 4 trimmed Top Flite - 18.8K
 
However, at this stage I realised something was not quite right
 

 
There was noticable vibration which I knew was down to the prop being out of balance.
 
RULE 3 - DON'T IGNORE WARNING SIGNS
 
On the second run the vibration became even worse - if you look at the picture you will see that the upper bar of the mounting cage had broken.
 
Anyway, three out of four bars will be enough I said to myself.
 
RULE 4 - DON'T CARRY ON IGNORING WARNING SIGNS
 
Now, I increased the compression and the revs increased to (for me to know and you to wonder!)
 
The vibration calmed down.
 
RULE 5 - THINGS DON'T CURE THEMSELVES
 
The next start up had me with a camera in one hand and the rev counter in the other. I was intending to film was I was seeing.
 
However, the propeller disintegrated - part of the blade just missed me - followed by a cracking sound and the engine flying off and biting me with what was left of the propeller.
 
One broken cage!
 

 
A bitten finger
 

 
RULE 6  - STAY BEHIND A RUNNING ENGINE. NOT AT THE SIDE OR IN FRONT!