In late May of 2001, I decided to purchase a few engine mods and other stuff. My first upgrade was 44cc ADA Racing Billet Heads (photos below). However, I soon incresed the compression even further by replacing these with R&D 42cc cast aluminum "Red Heads." Other mods I've installed included a change of reed valves & petals, shimming the carb needles and a TauCeti Flame Arrestor Kit (with Atlantis primers pressed into the carb adapters). I've also added a secondary bilge pump for "peace of mind" - And, it has gotten some use!

UPDATE 2002... Over winter we made a few changes to both watercraft: The STX work included new Boyesen Pro-57 reed petals, a new AP Designs three-piece seat cover and Hydroturf floor mats (tri-color). We also replaced STX the fuel filter and fuel lines and moved the primer up front, under the hood, for easier access (re-routed, off the return line). The Ultra needed new pump bearings: So, we shipped the pump to Impros. The Ultra exhaust was tweaked with MSD Pulse Width Modulated ECWI at the manifold end and an Inland Jet flow control valve set to 3.5psi at the stinger, feeding the waterbox.

R&D 42cc Ultra 150 Pro Series "Red" Heads - optional Girdle Kit not in use - 180 degree cooling hose fittings - Triple water outlets, forward mounted - Shimmed the carb needles to richen the mixture

Click image to enlarge...

• rule 500gph auto-bilge pump (in front of the motor)
  • This doen't make me faster, but it keep the bilge dry

Click here to view all mods/extras

Stock Ultra150 Engine	Expansion Chamber and heads removed
ADA Heads & TauCeti F/A Installed	Expansion Chamber Re-Installed View 1
Expansion Chamber Re-Installed View 2	Top Down View w/ Bilge Pump in site
Final View	View of ADA Heads