Hello, I have a Matrix TR with the Corsa 28, im having problems tuning the engine. If I lean it out to where it runs pretty good the temps climb to 300 deg+ and if I richin it up it runs like crap. Im running 20 % fuel, im about 3 turns out on the HSN ive got a good trail of smoke out the pipe but it gets hot as h.... I have 2 other cars that tune pretty easy but im starting to think this engine is crap. Any suggestions. Thanks.

Could be a couple things:
First have you checked the temp using a secondary method?
If your Temp gauge checks out ok then it time to start looking for aireaks(loose head screws, loose back plate loose carb ect..)
Laos check to see if the silicone flange gasket at the header ison correctly.

Hope this helps and keep us up to date

Usually, if the engine runs right, chances are it is fine. 300* is a little high, but it could be the temp guage, the lexan body, or maybe some loose screws like dogman said. Is the engine completely broken in? It should have at least 7-8 tanks before it will run very well. After about a gallon, it should be at peak performance.
Don't get discouraged and be patient.
Good luck

one other thing I would suggest is to check for air leaks in the fuel line... particularly where the filter is. You might even try eliminating the filter as a troubleshooting step. Also, just an FYI... there is an identical filter element in the bottom of the fuel tank, as there is in the external fuel filter module. That said, the external one is a bit superfluous.