All i know is that most (all) of the tamiya engines are sh*t. Thats why first got my old TG10i got a new motor for it straight away.
If i was you i would save up some money and buy a new engine. Novarossi, STS, RB, Force, Thunder Tiger.
PM me i have a Good engine that i will sell. Becasue i have no need for it any more.