ORIGINAL: ro347
Aside from lines and tank...is there anything else I could be missing? Whats the chance there might be a sealing issue with the engine? Im guessing I should probably run the engine again without the cowl on it to try and get a better idea.
If you are worried about exhaust grunge or fuel weeping back along the fuel lines through the firewall then running the engine without the cowl will tell you nothing as that would completely alter the airflow and oil travel. and absolute seal around fuel lines is not neccessary and you can actually do fine with a pretty big hole.
If you have oil grundge under the fuel tank its far more likely from weeping around the bung or around the plug tubes. You may want to tighten the compression screw.