Forgive me for my ignorance on stuff like this 
I own a Merc 402 40HP long shaft that is on my 14' runabout.
I've been doing some rough calculations on what to mix the oil/fuel at. I figured I was going to go by what the fellow said to me when I bought the engine.
"I don;t know te mixture ratio... I just add a can to each tank of gas. Runs a bit rich but I like it like that."
Now... this sounds a bit rough for my own likings.
#1. I have seen 3 sizes of cans at my local store. 500ml (.13gal), 750ml(.2 gal) and 1L(.26gal)
#2. The oil has 3 measurments on the back. 24:1, 50:1 and 100:1
#3. Depending on what can he was buying, none of his mixtures really come too close.
So.... I read the article in the engine FAQs about mixes. (Some GREAT information there) and looked at the Mercs. Then saw this...
--MERCURYs - ANY non-high performance Merc made after 1960 can handle a 50:1 mixture of fuel and oil. Racing motors will need more oil. I run 20:1 in my smaller Merc racers. Newer V6 high performance engines might need more and some require av-gas (100 octane)--
So how do I determine if my 402 is considered a high performance engine? It seems high performance to me when booting across the water... but is it really a high perf engine? Or should I just mix 50:1?
Sounds a bit noobish.... but I guess I am a noob
I own a Merc 402 40HP long shaft that is on my 14' runabout.
I've been doing some rough calculations on what to mix the oil/fuel at. I figured I was going to go by what the fellow said to me when I bought the engine.
"I don;t know te mixture ratio... I just add a can to each tank of gas. Runs a bit rich but I like it like that."
Now... this sounds a bit rough for my own likings.
#1. I have seen 3 sizes of cans at my local store. 500ml (.13gal), 750ml(.2 gal) and 1L(.26gal)
#2. The oil has 3 measurments on the back. 24:1, 50:1 and 100:1
#3. Depending on what can he was buying, none of his mixtures really come too close.
So.... I read the article in the engine FAQs about mixes. (Some GREAT information there) and looked at the Mercs. Then saw this...
--MERCURYs - ANY non-high performance Merc made after 1960 can handle a 50:1 mixture of fuel and oil. Racing motors will need more oil. I run 20:1 in my smaller Merc racers. Newer V6 high performance engines might need more and some require av-gas (100 octane)--
So how do I determine if my 402 is considered a high performance engine? It seems high performance to me when booting across the water... but is it really a high perf engine? Or should I just mix 50:1?
Sounds a bit noobish.... but I guess I am a noob
