RE: Engine break in
Cyborg,
XJet is perfectly right!
The TT.61GP is actually a .65 cid engine. This is probably to make up for the lesser specifications, with added cubic displacement.
You will need a genuine TT Pro cylinder head, or to go to a machinist (or a DIY shop), to make a Heli-Coil re-thread for the glow-plug.
It must be 1/4"-32 thread (UNEF).