mercury 1973 20 hp and 1982 9.8 max speed 6.2 mph!

[saabsaviorlee]

mercury 1973 20 hp and 1982 9.8 max speed 6.2 mph!een serviced with plugs and fluids within the last month. Both motors when paired with my 12.5' inflatable push me along at 6.2 mph! The common denominator is using the same tank and line. Both start fine, idle smooth when throttle up they max out at around 3400 rpm and won't budge past. With the 20 I tried disconnecting the fuel line and attempted to blow out any crud, once done I reconnected and when trying to throttle up was met with bogging and stalling. In neutral it sounded to idle up much higher than it was reaching in gear, does that point to anything in particular? Eventually it returned to my blistering pace of 6.2 at WOT. I have ordered a new tank, line, and bayonet style connector. What else am I missing?

 

[oldman570]

Re: mercury 1973 20 hp and 1982 9.8 max speed 6.2 mph!

If the tank vent is pluged or closed, the motors cannot pump enought fuel to let the motors get up to their top RPM. If the vent is clean and open then both motors have the carb problems or other electrical problems.
Oldman570