My mxt-7-180A has the fixed 56" prop per the prop log. Prop was new in 2000 and has about 1500 hrs. The tbo is 2000 hrs. Looking at getting a little more climb. The prop will only turn about 2350 max static even with 72-76 compressions. The prop is smooth and appears to track straight. My question is have folks with this similar setup found significant or worthwhile performance gains repitching and at what pitch? Or am I going to regret more of a climb pitch and dealing with over reving more easily?

Thanks,

John

I have a MX7-160. I repitched my prop from 54" to 52" at overhaul. I now have to watch not to exceed red line. It is 3 to 4 mph slower in cruise. There is a small increase in climb rate and a decrease in TO distance. Like all things airplane there are trade offs. What's important to you? Cruise or TO performance? With a fixed pitch you can't have both.

I'm having the same plane as the thread opener - MXT-7-180A with fix pitch and a 56 pitch prop on it.

Still working on my take off and landing technique, even though, I'm pretty happy already.
My question is more about the cruise - I got the O360 C4F with that prop - which RPM is suitable for cruising? is it the 'usual' 2400rpm as in the VP prop which might be the 75% power?
What is your experience and how are you cruising?

We have the same plane and engine/prop.

As is so typically the answer, it depends...

DA, altitude, pitch (climb or descent, up or down drafts, etc).

Usually the plane will run redline if I ask it up to about 7,500' DA. Over that there is not enough power to run redline so I can leave the throttle open all the way.

On takeoff I don't get to redline so its full throttle of course.

The problem is in cruise descents. Even at altitude where I'm making less than 75% power I have to throttle back to keep the tach in the green arc.

It is what it is, but I wish I had the C/S prop.

Also, as far as % power/RPM/DA Maule does not provide a chart but Lycoming does. Find it on their website. I printed it and keep it in the plane.