maybe he won't do an exchange for another engine but you off course can buy another one and put it in there.

Don't be afraid of the MDS yet....from my own experience and from what i have read from others you can run the MDS without any problems as long as you have the right combination of fuel and glow plug. For the fuel i would recommend 0% or 5% and you should get something like the Fox idle plug. That should keep the engine from quitting on you.

Like DMcquinn said, open the HS needle to 2.5 turns out and i would probably do the same with the LS and then slowly lean them out after several tanks.

what fuel, glow plug and prop are you using?