Re: One last stupid question>max safe RPM's for 70hp
Adjust the carb linkage where the center of the linkage roller is dead center with the scribe line of the throttle cam and "just touching" when the controls are in neutral.Use the throttle cable trunion and/or the roller lock screw for this adjustment setting.Make sure you spin the prop when shiifting when engine isn't running.Those carb flaps should be opening fully horizontal at wot setting,but not past.Setting the linkage roller should insure this.Also each carb flap has its own lock screw.All three should also fully close when controls are in neutral.<br /><br />21" prop is going to be too steep on a 70 hp engine unless its driving a rig under 800 lbs.19" maybe ,but final wot RPM test will dictate the final choice in prop pitch.<br /><br />What boat is this 70 pushing?Also insure that the engine is mounted to the transom where the lower unit anti-ventilation plate is running on the same plane as the boats bottom when trimmed level.Too deep equates to excessive exhaust back pressure and drag.Too high equates to exfcessive prop ventilation and prop blowout in turning maneuvers.Again only a watrer test can confirm final placement , as each hull and setup is unique.