Hi Biscuit,
Don't buy a ready to run, especially if it's not fiberglass, you will be disapointed. The styrene hulls fall to pieces.
The Wicked Angel, test run for a well known mag, started to crack up during the first test runs.
Stick with what you have got, it will be worth it in the end.
The SC engines do work, it's just a matter of sorting it out.
Most I C's can have problems at the start. I had an OS that nearly drove me mad, but now it's sorted, it starts first time every time. Other club members with electric starters look on in wonder as it starts first time every time, with a pull cord, while they spend ages with electric starters.
Remember, no pain no gain.
Bob