Mercruiser 170 timing

[ddrieck]

Hey all,
I would like to check and reset my timing if needed on my 1985 Mercuiser 170. I am at 1000 feet above sea level. Should I set my timing to 4, 6, or 8 degrees before top dead center on this old four banger?

 

[nola mike]

4

 

[Eric 3.7LX Alpha 1]

I've never seen any timing adjustments for the 470 in relation to elevation. The spec is 4°

 

[ddrieck]

I've never seen any timing adjustments for the 470 in relation to elevation. The spec is 4°

I lived in Casper, WY for 25 years and have now moved back to central Illinois. Out in Wyoming I always had to fine tune the timing and carbs for the higher elevation for max performance on my 2 stroke bass boat.

 

[Eric 3.7LX Alpha 1]

The factory Mercruiser manual #8 doesn't mention timing adjustments for elevation.
It mentions prop change only.

 

[ddrieck]

The boat runs great at the lake, shoots up out of the hole fast and jumps right on plane. Warmed her up on muffs in the driveway this afternoon and I checked the timing.... it was set at -2 degrees so bumped it up to 4 Degrees and she smoothed up at idle very nicely and revs much faster. I will be taking her out fishing this weekend and looks like she will run even better.

Thank you all for the info!!!!

 

[Eric 3.7LX Alpha 1]

Good luck and have fun!

 

[ddrieck]

Yup, setting the correct timing really woke the old girl up. Hit 40 mph with the timing set correctly with me and three other adults onboard. She would run out at 36 mph with the timing set at the -2ish I had originally found.