Lead Additives for Older Outboards?

[spoggy]

So, my 1971 1350 Merc was built before unleaded fuel became the standard, not just an anomaly. It was seriously before ethanol additives as well. For all my older engines, I've sought out ethanol free fuel and use it religiously. I also like sta-bil. What about adding lead back into the fuel as well? The whitepaper on the 71 1350 advises that the spark be retarded a few degrees with unleaded fuel. Is there any real advantage to adding lead back into the fuel?

[THEFERMANATOR]

The lead was a octane booster of sorts back in the day as well as a lubricant for valve seats. For your old outboard I wouldn't sweat it. Make sure the timing is set to spec or minus 2 degrees, and call it a day. The lead substitute you buy today will be of no benefit to you as you don't have exhaust valves and seats to worry about, and it does nothing for octane. If your concerned about it, run midgrade and call it a day.

[spoggy]

The lead was a octane booster of sorts back in the day as well as a lubricant for valve seats. For your old outboard I wouldn't sweat it. Make sure the timing is set to spec or minus 2 degrees, and call it a day. The lead substitute you buy today will be of no benefit to you as you don't have exhaust valves and seats to worry about, and it does nothing for octane. If your concerned about it, run midgrade and call it a day.

Can do! Thanks!

[smokeonthewater]

On the old mercs (mine is an 1150) I run ONLY premium and if you really wanna treat it good run aviation 100 low lead ($$) or race fuel ($$$$$$$)

Definitely retard the timing a few degrees if you will be running pump gas... That is a MUST with today's crappy gas.... even premium.

As Ferm indicated lead substitute isn't lead and won't help with octane so it's useless in these 2 strokes.

[smokeonthewater]

IIRC look for 20-21* btdc at wot.... I believe original was 23* when we still had good gas


also link n sync below:

http://www.johnsoldmercurysite.com/phpBB3/viewtopic.php?f=17&t=935&start=10