4800-5200 RPM according to the manual
It should idle at aprox 650 rpms warmed up.
Almost positive it's 50:1 Have a 650 65hp Merc and that's what it is.
Around 750 rpms on an automatic and 650 on a manual transmission.
On a 1997 Mercury Mountaineer : It came from the factory with either the Motorcraft BXT-65-650 battery ( or the optional Motorcraft BXT-65-850 battery ) ( that's BCI group size 65 , 650 or 850 cold cranking amps )
that would be good for the cold idle and should drop three times as the car warms up and should idle about 650 to 800 auto trans
BCI group 65 ( such as Motorcraft BXT-65-650 ) 650 cold cranking amp (CCA)
Good enough that Mercury chose this block design for their 650 cylinders when they arrived in 1972.
10/30
An 65 hp Mercury outboard, serial number 4266564 is a 1975 year model.
50:1
A 65 hp Mercury outboard, serial number 4574019, is a 1976 year model.
The questions should read '650 p c in the UK? Answer: 650 parliamentary constituencies in the UK!