Hi All,
i've been reading this forum for a couple of weeks and I have searched and read all of the articles on the olds 455 and jets in general. I am new to boating and I recently bought a 1973 Rogers jet boat with an olds 455 and berkely pump. This boat is old it has stock everything. I don't need super performance out of it but i do want it to run like new.
This is how it behaves:
It planes out at 3800 RPM and I haven't pushed it above 4600 RPMs and at these revolutions it goes 50 miles an hour (GPS). I know these boats should do at least 60~65 MPH. I looked at the carburator at WOT and noticed that the secondary butterfly valve never opens so its starving two jets from air. The engine runs great no misfiring smooth like there is nothing wrong. But there is this lack of power! I think I want to change the carburator and intake manifold. Carburator for the reason mention above and intake manifold because it rusty since it was sitting for 5 years.
Can you guys please let me know how to get designed power from this engine and maybe carburator and manifold recommendations. Also maybe some pointers about the impeller. i don't understand what loose means (in terms of impellers anyways).
Thank You Very Much!