I have an OS max 32sx-h engine on my ergo 30. It lately will fly for about 30 seconds with good engine response. After that the rpms drop off to where it will barely climb. I tried adjusting carb. Any suggestions.

Sounds as though you are getting it hot

Any Suggestions - when I first got it, it ran fine. If I let it idle for about 10 seconds its ready to go for another 30 seconds. This just started lately.

Did you change to a different fuel?

The waiting and trying again and it running fine is a pretty good indication that it is getting hot.

Maybe you are running too lean

You might have a kinked or clogged fuel pickup or muffler pressure/vent line. A clogged vent line will allow a vacuum to develop in the tank until the engine can no longer draw enough fuel to run wihout going lean. The time at idle allows the vacuum to bleed off and the process can start again. A kinked or folded clunk line in the tank can produce similar lean runs and quits.

Good luck.

In my limited experiences it sound like you may have debris in your carb, or fuel line, check your clunk my be stuck at the top of the tank.

I had a similar issue with my Evolution .46 just today. I thought that being thoroughly broken in by now, that I could lean it out just a bit (only about 3-4 clicks leaner, prob less than 1/8 turn)
Well, the next two times I tried to taxi for takeoff, the engine would rev, and then begin to bog down and lose power.
I reset the needle back to the richer (original) position and things have been fine since...just a thought.
Bob

Today I had a problem with a friend's OS .46 LA mounted on a trainer plane. It would start up fine and then in flight gradually lose power. I would land the plane and the motor would be hotter than normal. Let sit for a while and it starts back up again and then repeats the loss of power thing in the air. Made several adjustments including changing glow plug and flushing out all lines and carb. Still gets hot. When putting the plane away for the day I noticed that the motor mounting bolts were all loose and would allow the motor to move about maybe 1/16". Could this condition cause vibration that would in turn cause the motor to rund lean. I have not had the chance to tighten the bolts and test run the motor. Anybody, what do you think?
Running Omega pink 10% fuel, works very well in my other motors.

The vibrating will make them run hot

I once accidently switched the vent and carb line after filling the tank. Kept dead sticking within 30 seconds of takeoff.

Thanks for the reply on the possibility of vibration causing a motor to run hot.
Today I replaced and tightened the mounting bolts on the OS .46 LA and went out to the field to try it out.
It started right up and appeared to be running OK on the starting stand. I then noticed that fuel was coming out of the head and bubbling as the motor was running. AHA!! could this be the culprit?
I then tightened the headbolts and restarted the motor. Let it run at full throttle for 3 minutes on the stand. Ran steady and did not slow down or get hot.
I then put the airplane in the air and flew the entire tank out. Didn't mis a beat even in loops and rolls. After that I put a student on the buddy box and we completedl three more flights without a hitch.
Now what I wonder was the lean hot run caused by the vibration caused by the loose mounting bolts or was it the loose head bolts? Or a combination of both?
Just glad to have it operating again. Thanks for your information.

Check the tightness of the mounting bolts. Loose bolts can cause vibration which will cause bubbles in the fuel line.
Also, check the head bolts to make sure they are tight.
I had this problem with an OS and it turned out to be a combination of these two problems.

Is the prop balanced?