sbt 657x engine

Hello fellow water bike owners, I recently came into an issue(s) on my 1995 sea doo spx with the 657x engine. I acquired this ski in no-start condition. I did a full fuel system rebuild(carb rebuild, fuel line replacement, fuel baffle replacement) since it had a fuel issue, and it started and I...

Motor was supposed to go into a 95 Speedster and all the assembly parts were taken from the boat. The reman core has never been started and was purchased with the SBT complete gasket kit and break-in oil that will come with it. Still have all original purchase reciepts as well, however, the core...

Anyone put one in? I found some old threads indicating some issues. I've nursed my 95 Speedster along for the last couple of years with my mechanic's help, and it's finally time to replace the port engine. He is directing me to the SBT engines. Any feedback from anyone on these?