Looking to see if anyone knows what type of head/button I need to change over to single plug from the dual plug? I had 4 tanks through the new engine before a 6-1/2 year break from the boats and now I'm looking to re-wet my feet again, pun intended. Both plugs blew when I gave her wot on the 4th tank, to big of prop, that gets pricey two at a time. I'm sport running with 20% nitro in 1/8 scale hydro. THanks for any help. Some one told me it takes two gallons to break this engine in!