Fuel mixture for 66 merc 650

[tikilounger]

Going to attempt to fire up the Merc and first off, does anyone know what the fuel/oil ratio for a 66 merc 650?

 

["G"]

Re: Fuel mixture for 66 merc 650

The 66 65 HP I had used 50-1. I used Amsoil 100-1 and found it to run like a champ. Smokeless idle at 450rpm and never a miss at idle nor all the way through to wot. Some swear by Amsoil... some swear at it. No big deal.
The key; use a good oil and make sure it is ashless and it's a TCW rated oil. Be careful of the off brands out of the super market. Use Merc, Evinrude, Johnson, any major manufacturers oil for two stroke outboards.

 

[cannonford57]

Re: Fuel mixture for 66 merc 650

G nailed it .the mixture is the lifeblood of your engine....since its got some years on it (like most of us) instead of 50:1 i'd do 3 oz. to the gal...

 

[JB]

Re: Fuel mixture for 66 merc 650

"Use Merc, Evinrude, Johnson, any major manufacturers oil for two stroke outboards."

MYTH. None of those people make their own oil. The oil is made by the same people who make the "off brand" oils, and to the same specs.

Wal Mart SuperTech is as good for your engine as any non-synthetic and a lot less bux.

 

[76canaventure]

Re: Fuel mixture for 66 merc 650

Good Morning!
Definitely agree with JB, all oil with a TC-W3 code on the label meets the same certification testing criteria for this specification, regardless of branding. I prefer to buy by price, the best oil for me is the one that leaves more $$ in my pocket. Is one brand better than another? I guess that would depend on how much you are willing to argue about what shade of blue the sky is today.
Just my .02, I'm off to the lake!
Regards,

 

[tikilounger]

Re: Fuel mixture for 66 merc 650

Thank you all for your help. I am off to do some mixing.

 

[Bob_VT]

Re: Fuel mixture for 66 merc 650

I have the exact same engine and it is fussy. Make sure you mix the oil completely and properly. There is no such thing as over mixing but too much oil has an effect..... too little will trash the motor..... be precise!

 

[tikilounger]

Re: Fuel mixture for 66 merc 650

Please explain fussy. As I can only go forward with the care of the merc. Not sure how well it was taken care of in the past. Glad to meet you, nice to meet someone familiar with my possible pitfalls.
Today was my first day of possession. Battery was dead, no fuel line, but was glad to get it to turn over. Are the fittings for the fuel line readily available? Interior completely shot, floor, sides, transom, but the air horn works great.