1978 Mercury 500/50hp help!!!

[jhande]

I was searching online for a repair manual. I came across a link for a free PDF download which lead me here = https://www.downloadboatmanuals.com/motors/mercury/
The only manual I was able to find in the listing was = Mercury 1971-1985 Service manual [PDF, ENG, 2.9 MB].pdf. BUT I don't believe it's the right one. In the manual it states =
Break-in Gasoline/Oil Ratio
Manual Start Models - Pre-mixed Gasoline and Oil 25:1
Electric Start Models - 50:1 (In Fuel Tank)
After Break-in Gasoline/Oil Ratio
Manual Start Models - Pre-mixed Gasoline and Oil 50:1
Electric Start Models - Straight Gasoline That doesn't sound right at all.

Can anyone suggest a good repair manual and maybe where to look/buy?

 

[merc850]

Look for Mercury Marine 1975 thru 1978 C-90-75512 the break in mix is 25:1 the run mix is 50:1; your motor should've be broken in years ago.

 

[racerone]

Just an example of poor information found in some manuals.-----That information might be for a motor with automatic oil injection system.------If you trust some of these manuals you could be making expensive mistakes !!!