You can get a muffler for it. (they call it a spark arrester) I put one on mine and it purrs like a kitten. Kind of pricey but wouldn't be without it. I also hate the scream.
Ike, when Case started installing wastegate turbochargers on 2166_88s in 1996 to comply with offroad emissions, they had a definite change in "exhaust tone" from the older Axial-Flows with CDC engines. This sounds continues to this day with 2366_88s. It does take some getting used to and there is nothing wrong.
You are not meant to regularly clean the air filter. Only when the indicator comes on. You are more likely to do damage to the filter and motor by over cleaning than not cleaning. I clean my 2366 about once per season ( if the light comes on)
I see your point about not cleaning so often. We have two filters that we rotate throughout a season especially in dusty seasons and we replace the inner filter once in a great while because you are not supposed to blow that out. I also have 2 for the cab and the engine and such and I replace them every so often and clean out the other for next time. I have a 89' 1660 and I'm not sure if the indicator works or not on the air cleaner, it is supposed to be red when it's time to change the filter but when do you check this, when the engine is running or doesn't it matter if a filter becomes plugged or dirty it should stay where the level of suction is or does it resetIJ let me know. I always change them for peace of mind and haven't had a problem yet *knock on wood*. How many hours do you run on yours before replacingIJ What do you do with the cab filterIJ