Randy - Nope, no regulator!!! It's not recommended but a little birdy told me all the KO gear is tested at much higher voltage so it's safe to use. Not sure about the other mfg's though.
Garen - Find out more!
Ice_nl - It's hard to say without looking at the engine in person. Possibly just finally wore out if the engine was old/used a lot. With the exaust rubbers, make sure to put your pipe/header together and attach it to the engine. Then fit/adjust the pipe wire only to hold it in place - not to pull or stretch the pipe/header into a different position.