Yes Capt'n, I assemble the engines, test run them, and adjust the carb on every one we sell. I've done about 30 of them so far and all have been great runners. I did get one back yesterday, the only one so far, and I should have caught the problem before it left, added a new item to QC checklist. I have been running the snot out of two of them since August and so far they are doing great. Nice and tight package for 40cc and spinning a 20x8 JXF at around 6700 right out of the gate. From us these engines have a one year warranty, assembled and tested, if you buy them elsewhere in kit form your only warranty is that all the parts are in the box when you open it, from there you have 30 feet or 30 seconds whichever comes first.

Jody