The 84 inch by bonzi is an awesome model. Purchased my hull in August 2014 installed two twin cylinder gas powered motors hooked to custom made water jets. Everything had to be custom made including the couplers as these motors are very fast and standard items off the shelf would not hold up. I used all 1/4 scale servos with metal gears as well as half gallon tanks for each motor to get some long run times.''
The jet drives worked great and is very reliable. The set up was very complicated due to the twin engines. I also installed clutches and a water cooling system which exits through the exhaust system. It is a very expensive project. Jet drives were 1000 and the motors each run 1400 and everything has to be custom made including the water tight box because of the large servos. I used a trim system and bildge pump system to keep her dry in case of issue the ram sump pump works well. The model is very heavy but a radar gun clocked her at 65 miles per hours on the straight run which we could never do in the turns. Since we used jet drives and it needs a good turn area and has reverse whne the buckets goe down needing an additional servo. This month she is being torn down and getting custom paint so we can go to Toledo and show her off. The graphics will be applied and we named her screaming eagle. 6 months went into the project. MOtors were slightly modified with tuned pipes. We also found that a 53 degree impellor worked best after extensive testing as the water jet was made from billet alunimum in order to hold together. Rated horsepower is over 18 at 3500 rpm with a max rpm at 16000 but have not taken her that far other than bench testing. Good luck.