From the pictures you posted of the field you are cutting it looks like the knives might be mounted in the wrong direction. Cutting on the backside maybe. I know that sounds drastic but those long shoots left standing shouldn't be there. It makes sense what you said about the front holding the stalks and not letting it get cut but the front of the mower is going to be higher than the tip of the knives. Correct me here if I'm wrong about the height. That's the way my Mott is.
Your Jubilee should have enough power to run your flail as long as you are running it at PTO rpm. With the sherman transmission you have a low enough gear. You will have to go a lot slower than you would with a rotary cutter especially until you get the grass knocked down but something is surely wrong. Take that scraper off the roller like Leonze mentioned that will eliminate one of the things that may be giving you trouble. Most mowers don't have them anyway.
1. Make sure the knives have been installed correctly and in the right direction.
2. Take the scraper off the roller.
3. While sitting on smooth ground or concrete pad adjust the roller up or down to the desired
height of your cut. Do this with the 3 point hookup on the mower is vertical.
4. Cut slowly at a high rpm. All tractors are built to run at PTO rpm for hours at a time. Most
like it better than slow rpm's. My old ford likes it just a little slower than pto speed but still
very close.
Hope you don't get a bad taste about your new implement maybe it's something you and/or the crew that put it together missed somewhere. Who knows you might have the toughest grass in the world and everything else is just fine.
Wish I could offer some expert advice here but just posting my :2cents: worth.
