I have a B & S 17 hp motor that has about 170 hours on it from new. It had a rattly motor compared to the Kawasaki motor in my previous John Deere ride on. It is 1 year out of its official warranty. Recently the motor just stopped and wouldn't restart. On inspection it was found that the con rod had broken and caused other damage in the motor.
I was told by a small engine mechanic with 40 years experience in the trade that this was a known fault with this motor that was subsequently rectified by B & S . It was apparently caused by a faulty balancer in the motor.

Does anyone know if this scenario is correct ? Thanks Allistair

Did you notice the ad they put on your post, might get $75 https://lawnmowerclass.com/

I would check with B&S, if there was a known issue they have to tell you. Ask a few mower dealers about B&S first to see if they heard and/or agree this is true. I have never heard it but that means little if the next guy has heard it.

About 15 years ago, they had problems with connecting rods ,but that was the last I know of.then they had a cylinder gulling problem.
Most recently there was a camshaft promblem.

Sorry Allistair, ads come and go, the ad I saw is now gone from your post so click on my link If this pans out somebody owes me $225