Well i was stupid and was running my evader on the beach with no body on (i know i was complacent) and fliped it upside down, it was idling for a good 20-30 seconds before i could flip it back over then it just stoped. i saw that the airfilter was completely covered in sand so i figured it was just starved for air and i needed to clean the filter, i did that and cleaned the engine off and tried to start it with no success. Ive tried changing the glow plug, and taking the engine apart completely cleaning and re lubing everything no go still. i did find some sand in the tube in between the filter and the carb, the engine also apears to have no compression. Am i looking at a new engine? Is there anything else i can look for/fix/replace that may fix the problem or did i just ruin a perfectly good engine. Oh yes the engine was broken in and tuned by the book and there are no signs of any overheating anywhere. Which OS engine is it anyways if i do have to replace it? Thank you very much for any help.

When the engine is cold, if you can easily turn the flywheel with little or no resistance, you need a rebuild.