friend of mine lost his son to a bad set of bellows. teenage son bought a used boat and took it to a mechanic for a check up. mech said it needs a set of bellows, kid says maybe later, these look ok to me. took it out in the gulf, got a garbled 911 call 4 hours later. found the boat swamped next morning. found his buddy on the beach barely alive, never found his son. i am not an i/o guy, but these guys say change them, i'd do it.