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Old Evinrude Oil Ratio
- Thread starter chords
- Start date
polarisrider1
New member
I am thinking 32:1 and carry extra plugs. Actually Amsoil say's 50:1 will be fine. The gas and oils back in the day were not as good as todays lubricants. (so they say). Must be some truth to it, look how long plugs last now.
booondocker
New member
It is the oil technology that has changed and allowed 50:1 use. Using any higher concentrations would cause more harm than good, fouling the plugs which is not fun to change out while you drift around in a boat.
Only time you need to use ratio that is closer is if the motor is running hot, such as in a chainsaw or weed whacker. That is still mostly a safety precaution...but be sure you are using TC-3 oils...some stuff is cheaper but not rated and that just means that they don't have the right stuff to make the grade.
I have a handful of old motors made in 40's and 50's and they all say 16:1 on them and I use 50:1 and have never had to rebuild them.
Only time you need to use ratio that is closer is if the motor is running hot, such as in a chainsaw or weed whacker. That is still mostly a safety precaution...but be sure you are using TC-3 oils...some stuff is cheaper but not rated and that just means that they don't have the right stuff to make the grade.
I have a handful of old motors made in 40's and 50's and they all say 16:1 on them and I use 50:1 and have never had to rebuild them.
Actually AmsOil premix used to be 100:1, not sure if that is their recommendation anymore, but it used to be. We ran ALL our old TX's from the early 70's mixed to that ratio. Never had a motor issue once after switching to that ratio. I don't think it matters what motor.
It is the oil technology that has changed and allowed 50:1 use. Using any higher concentrations would cause more harm than good, fouling the plugs which is not fun to change out while you drift around in a boat.
Only time you need to use ratio that is closer is if the motor is running hot, such as in a chainsaw or weed whacker. That is still mostly a safety precaution...but be sure you are using TC-3 oils...some stuff is cheaper but not rated and that just means that they don't have the right stuff to make the grade.
I have a handful of old motors made in 40's and 50's and they all say 16:1 on them and I use 50:1 and have never had to rebuild them.
He's got it!!! I would stay away from any synthetic oils(100:1) as they are designed for tighter tolerance which I'm sure you don't have in that beauty of a motor. "Old Iron- Great Old History"
Any OMC with double hose gas tank needs a quart of oil to 6 gals of gas,(cruiseaday tank) because bushings were used on piston pins instead of needle bearings. Oil is alot cheaper than vintage parts and how many tanks will you run in 1 season? New oil is definatly alot better than 60;s stuff!! pennzzoly not the best for vintage if you read tcw-3 ,tcw-111 ratings.let them old babys smoke a little and enjoy!
anonomoose
New member
If you use a quart per tank of gas with the newer TCW oils, better take lots of plugs along...you are going to foul a bunch of them. These oils won't burn out like the older oils used to and the residue will cause the deposits to collect at a much higher rate. This is a bad thing...so contrary to the "more is better" beliefs, just don't do it!
Here is a good broad explaination of 2 stroke oil used in marine applications, mainly PWC. But the principles are the same no matter what you use your oil in.
http://www.sea-doo.net/techarticles/oil/oil.htm
Here is a good broad explaination of 2 stroke oil used in marine applications, mainly PWC. But the principles are the same no matter what you use your oil in.
http://www.sea-doo.net/techarticles/oil/oil.htm
plugs and oil still cheaper than vintage pistons. not more is better, but following oem specs. even with point ignition and carb adjusted right its hard to foul a plug unless constant low speed operation on vintage 50;s 60;s,omc;s mercs with a quart to 6 gal recomended mix. some 1980;s omc had 100/1 mix with no problem. They were engineered to run that way. double hose omc's had piston pin bushings not needle bearings. they need more oil or your going to have issues worst than fouled plugs! .02 worth ,school of hard knocks !! tuition was high !!