I have a deere 737 that I purchased brand new, oil has been changed every 25 hours with mobile 1 synthetic. I tried to crank it this morning and it spits sputters and backfires then cranks. I noticed right off the bat that is was running badly, like on one cylinder. I'm thinking, gee, yesterday my BP blower and hedge clippers tore up, wtf else can go wrong. I drive 30 miles to the dealer to be greeted by a a@@hole tech that starts telling me that I put in the wrong oil should have been serviced more often, bla bla. I tell the jerk there is no one any ticker than me about taking care of their equipment. First he changes the oil, then the plugs and fuel filter. Fires it up then tells me it sound's find, I tell him no it does not sound find. He reaches behind engine and unplugs the right plug wire, nothing changes, unplug the left one and it dies instantly, Oh, he says, its the coil (my thoughts from the beginning). Tells me to leave it with him. Get a call just few minutes ago and they had the firing problem fixed but had to pull the heads and found bent push rods and messed up valves. Was going to call me back when checking it further, I don't trust these jerks no farther that I can see them, thinking about just going and picking it up if I can get it back on the trailor. Am waiting to see what they call back and say. They may be telling the truth but I feel like they are trying to hang it to me. I can't believe this engine only lasted 650 friggin hours!! If it is the engine there will be no more kaw. engines for me. And to top it off came back to get my exmark and the deck belt broke on it on the same yard I started on with the deere so I said the h*ll with it and came home!