1983 Mercury 115 setting wot timing?

[toybuilder039]

When doing a link and sync on my 115 Mercury inline6 it says to set the timing to 21 degrees btdc which I understand but says to err to side of caution. Does that mean you would be better to set at 22btdc or 20btdc?

 

[jimmbo]

It means 21 degrees before TDC

 

[toybuilder039]

Would advancing to 22 make it run hotter or cooler?

 

[jimmbo]

Well, advancing the timing can, in theory, make an engine put out more power, right to the point of self destruction. Combustion chamber and cylinder head temp would be higher while exhaust gas temps would probably be cooler. Don't advance the timing past the spec. You can hear an auto/truck engine pinging, warning you of preignition and detonation. You'd never hear it when it happens in an outboard, the first sound of it happening is usually the last sound you will hear from that engine.

 

[toybuilder039]

Yeah I won't to set to safe side just didn't no which way that was. Thanks