There's another thread, where PLUM CRAZY had an issue with his SPE26 and he had to adjust the carby. Check out POST#52 in the following thread ...

http://www.rcuniverse.com/forum/m_48...tm.htm#4800289

It might be something similar to this.

Another thing you may want to check it to see if your piston rings are stuck in their respective grooves (they should be free).

-R