I got >95 on the writtens, and there are plenty of ASA and other books out there to study the writtens from, so I'm assuming you are talking about the orals and practicals?
There is a General section, two Airframe sections, and a Powerplant section. All of the oral exam questions and practical exam projects are randomly generated. The DME doesn't even know what is on the test until, I think, the day before. LOTS of fire and fire protection questions were in EVERY of the sections of my oral test. LOTS and LOTS and LOTS. I missed one General question, one Airframe question, and three Powerplant questions. Powerplant isn't my strongest subject because I only occasionally get to help our engine guy out, and we only have GE 700/701 Turbine engines. I knew it was my weak subject before I went in.
They still ask about pressure carbs and float carbs, I don't remember radial engine firing order questions, but there were plenty of radial engine questions like hydraulic lock, and cooling, and lots of other recip questions that could apply to O or R engines. Stuff like engine ignition, bearings, magnetos, valve overlap, engine and engine compartment fire protection, etc. I was surprised at how much of the powerplant oral was about turbine engines. I would say probably about 60% of the powerplant section pertained to turbines.
There was also wood, fabric, dope questions, aircraft finishes, aircraft registration lettering (14CFR45), rigging, maths, physics, electrical systems ("SLA" seems to be the new buzzword because it was used a lot), engine instruments, LOTS of fire protection system questions, oxygen systems, cabin pressurization, constant-speed props, corrosion, landing gear, hydraulics, pneumatics, fuel systems, FARs, and I can't remember what else. Lots of stuff though.
My practicals were to determine correct size rivets for a sheetmetal patch and then make a rivet layout, read/use a micrometer, make a maintenance entry (14CFR43.9), make a 100-hour inspection entry (14CFR43.11), determine if a repair is major or minor (14CFR43 Appendix A), use a Service Bulletin, test a thermocouple for resistance and/or continuity, bend tubing and flare/swage both ends so it fits in a specific spot in a jig, inspect engine compartment for squawks, troubleshoot pitot heat system, replace brake pad linings, determine weight and balance after removing something and adding something, determine if a constant-speed propeller is within acceptable pitch range, determine the removal and installation procedure for a PT6 engine on a KA200, and there might be some others that I can't think of right now, but that was the bulk of it.
I passed every practical test item without any problem, I was well prepared. When I left, the examiner said he was very impressed and was also going to change one of the practical tests to be performed the way that I did it because my technique was different and better than any that he had ever seen for that particular one. I thanked him, and he thanked me back saying, it was a privilege to have an applicant that made it so easy for him. I asked him what he meant, and he gave me a few horror stories of applicants that weren't ready to test, and some other horror stories of things that happened during his tenure as a DME.
