Small Engine Troubleshooting Problems? Ask a Mechanic Now.
The carburetor is a Walbro and doesn't look like the directions you sent for the mikuni. I have been out of town but need to get this issue resolved in the next few days.
I found another guide to my Walbro carburetor, removed it, disassembled it completely and cleaned it with carb cleaner and used a small wire to make sure all areas were clear. I didn't see anything wrong with it via disassembly, but cleaned all areas anyway. After reassembly, Restarted the mower, but I'm having the same problem. It was easier to get it to the point of running without the choke, but engaging the blade still makes it cut off. After running the engine for a good five minutes, I was able to engage the blade...sounded like it was running great for about 2-3 minutes, then went right back to cutting off. When restarting, it revved (by itself) again, then cut off...same thing when restarting several times.