What would happen is, the MO (let's say it's for $1,000) clears, your banks shows the deposit of $1,000, or appears to, you give them the "change" Let's say $600. Then down the road, the counterfeit MO for $1,000 is discovered, and the bank withdraws $1,000 (the $400 that is left in there for the price of the motor, and the $600 you gave back as "change".)
So your out $600 out of your pocket, and the $400 that never was... and if your "Lucky" they never did make the proper arrangements to get the motor shipped, and you might still have that?
Sell it to Fish On, he's in the US... I won't even entertain doing ANY transaction with any one outside the US unless I know them. Like Hansi, Knut, Bjorn, etc...
If it's not for the correct amount, No Deal... or anything above and beyond your asking price, just tell them that's the handling charge! Lol...