Logo

75hp Mercury outboard 4-cylinder 2-stroke fuel/oil mixture ration and other questions

Jerax

New member
Hello,

first i'd like to introduce myself since i'm new to this forum. My name is Jörg and i'm from Austria, Europe. I'm owning a boat since three years now and recently upgraded to an old Elan Boat with a 75hp Mercury outboard.

Although i do own a service manual there are several questions that are not mentioned there (and it dont have a regualar users manual)

Firstly the engine is supposed to be a 75hp 4-cylinders. So it should be model year 84-86 although i couldnt assure this with the serial number as it doesnt fit with any of the references found on the web. (Serial is 9453658)

My questions are:

1.) can anyone confirm that it is the engine i think it is?
2.) what's the proper oil/gas mixture - previous owner said he used 1:25 but that seems a lot to me considering the supposed construction year
3.) what is the current output of the power generator/coil on this engine (i'd like to operate a fairly high powered hifi an dont want to drain battery)
4.) there's a problem with the rpm-meter. The instrument in the dashboard seems to work (needle moves for a moment when main power switch is closed) but it doesnt show the revs of the engine. where/how would i best start to search for the cause of this issue?

Thanks in advance for your Feedback

best regards

Jörg
 
Jörg,

ive vey just joined the Marine Engine forum today.
i have a similar design and vintage Mercury engine (4-cyl; 75 HP; 1986)
i have been successful using 50:1 gas-oil
i also have the same question about the voltage/generator rating based on my interest in running a Bluetooth/amplifier

i do own a good shop manual; I'll see what it says about your serial number
My Mercury powers a 1972 Boston Whaler in Massachusetts (US)

Best, Neil
 
Back
Top