I was referring to adding a shut off valve to a Toro engine that would be on a different mower. Not saying to do anything to his current sputtering mower.
Keep grinding at your dealer to fix or get you another model. This is known issue so get something with a Toro engine instead. If you want to store vertically put shut off valve in fuel line (I did) and it will store nicely. Get rid of Mr. Sputter asap my dealer told me to stay away from B&S...
I like my JD X350. It has exceeded my expectations in mulching, bagging, side discharge and cut quality. Excellent ride with minimal vibrations. No weird quirks, very high quality and a real enjoyment to use.
Nice write up on your X380 post Mike. I'm wondering the model # of the blades that came with your mower. JD lists that the standard blades have a wing height of 0.858 in and the high lift blades have a wing height of 1.370 in. for the 48" AccelDeep deck.
Step 2 should not require a ratchet strap. At least it didn't for me. I suggest you go through the manual for installing the deck again. I've done my x350 no issues.
Suggest you might consider a John Deere. I looked at Cub but decided JD would bag, mulch, and side discharge better. My JD exceeded all my expectations.