I have a DA 100 on my Yak with MTW-75 Cannistor mufflers with a 3 bladed 25X12 Mezjik Carbon Prop. Does anyone have this combo and can tell me what a good RPM should be. Im using 32:1 oil/fuel mix with high quality fuel. Can anyone tell me what a good starting point for high and low needle valves? Mine does not seem have the power like it should, temps on the ground are around 210 max and im producing 38 pounds of thrust. My friends 3W is producing 48 pounds of thrust with a 28X10 2 blade prop. The engine seems wo be much more crisp the 1st 2 or 3 min of flight but then the RPMs seem to drop off, almost like its lean. My RPM is around 5700 and drops to like 5500.

Im worried maybe there is something wrong with the engine.

Starting needle settings will be from 1-1/2 to 2 turns open for both needles. You set the tune from that point. The base settings are only good for getting the engine started, from there it must be tuned for the fuel, prop, and location. If you have never touched the needles therein lies the problem. BTW, the 3W has more power in any case, so you're comparing apples to oranges.

You mention you are on 32:1. Is this broken in yet? If not then the three blade is too much load right now. You need to run a 27X10 for breakin for at least 5 gallons

It should be broke in by now but I will go and try the 2 blade I guess so how that works for me

A way to see if it has overheated is look closely at the color of the cylinders. If they have a pink color the engine has been heated up to the point of being overheated, the darker the pink the more it has been overheated.

interesting i did notice a pinkish color I think ill go check, I bought the engine used suppose to only have about 16 tanks through it. Going to be mad if the engine is damaged

no they dont look pinkish, I will check again out in sun light. The engine looks new the mufflers that came with only had alittle build up not much. Compression seems fine. When I ran it on the ground Sat for 1st time I checked temp and at the hottest temp was low 200s like 210 if I remember correctly. The engine should run the hottest on the ground, next time I will run it on the ground for a long time at full throttle and see just how hot it does get and see if the RPMS bleed off. If they dont and its not to hot, then it has to be a pressure issue causing my settings to change with alt or the engine has some kind of dmg.