Good Question. I do not have the power that I think the boat should have. Under a big load (8 to 10 adults) the rpm will not go over 3000rpm. Runs (and sounds) fine with with just a couple of people on it (rpm 4700) I am going through the list of of possible causes of low WOT.
1. Fuel good
2. Prop Correct
3. Fuel pick up almost 3 on suction... not sure about (or where) anti siphone valve
4. oil was 2 quarts high when I purchased 2 months ago
5. No Marine growth
6. gear ratio on outdrive correct
7. Throttle body air intake cleaned
8. had drive off and blew air through exhaust and it seems fine
9. All cylinder compression 170 to 180 after a head gasket change
10. Throttle body jets look good. Have repair kit in the mail will install this week
11. Fuel pump pressure and vacuum fine but have not checked when under a full load (8 or more adults)
12. boat loaded under max capacity of people.
13. Not over heating. Purchased boat without a thermostat not knowing and was told sensor was bad. When installing new thermostat I found pieces of the impeller stuck in housing. I also think this is why I had to replace head gasket after 15 hours after purchasing because the the impeller pieces blocking water flow in engine block/head.
15. linkage looks fine
New plugs, wires, distributor, Timing set to 8 degrees in service mode. no codes present
