I thought some of your might be interested in the mods we did to the CAT today. In my opinion the manifold where the quick connects hook up to the machine is very restrictive. Its even more restrictive on the standard size quick connects that I used to run the standard flow mower. From day one I felt the mower was lacking on the 289 compared to the 287 we used to run it on but I just figured that it was due to the 1000 or so hard hours of use it has clocked. Last week I ran the mower on a standard flow 289 and noticed it still has some poop to it and that I might just have a flow restriction on the Hi Flow 289. So here is the fix You can see that the standard size fitting on bottom is restricted by the 90 and the bend. After talking to the service manager at Mustang CAT in Houston he offered to bore out the manifold for us and gave us new fittings including the ones for the mulcher. We also went a step further and bought the large fittings for the mower too so it will run off of the larger quick connects on top and not be limited by the 90 elbow on the bottom. You can see the difference stock is on the right and the drilled out ones are on the left. You can see in the top pic what size quick connect we jumped up to I believe its called an A size but I could be wrong about that.