I am very confused about gas to oil ratio's. The owners manual for my 1958 evinrude fleetwin says to use a 1/2 pint per gallon. With 8 oz in a 1/2 pt and 128 oz in a gallon, I think, that is a 16-1 ratio. However I see people on here and elsewhere stating to use 20:1, 24:1, 40:1, etc. Is it the modern oil or what? How can one be assurred of using the right ratio?
The explation I heard was if you had babbit type bearings you use 24:1, If you had needle bearings you could use 50:1. I think the correct ratio for your motor is supposed to be 24:1. If your motor has needle bearings on the crank and rods, can't remember what year they changed, you can use 50:1. This is one of the items that everybody has there own theory on.
In 1958 16:1 was the correct ratio using 30W non-detergent motor oil.
This is 51 years later. Now we use TC-W3 outboard oil instead.
45 Years ago, OMC (who made your engine) said to use a 24:1 mix (1 quart TC-W3 oil per 6 gallon tank) for all engines they made before 1964 and a 50:1 mix (1 pint TC-W3 oil per 6 gallon tank) for all engines made after 1964.
More recently BRP (who owns the brand) revised the recommended mix for 1950 and earlier engines, but the 1958 engine specs stayed at 24:1. That is the official word.
You will get all sorts of recommendations from people who know more than the people who designed and built your engine (and don't have to bear the cost if you blow it up using their infinite knowledge). If you take their advice you deserve whatever happens.
It will smoke more than it needs to, less power than it could have, build carbon more than it needs to, score pistons and cylinders more than it needs and fowl plugs more often....
Lord have mercy! What will happen or what will be the effect if I use this tc-w3 oil at a 16:1 ratio?
are you worried about a tank full that you have at 16:1?one tank at 16 :1 will do absolutly sweet nothing to your motor,your motor will not die ,sieze ,rust away or anything else.use it up then go to 24:1 as stated .it may smoke a little more for that tank and maybe just maybe foul a plug at worst but i doubt it.carry a spare set of plugs as you should always anyways.
Ooops! I missed by a year. That is the revision I mentioned. 20:1 calls for 38.4 oz TC-W3 per 6 gallons of gas. That is a quart plus 6.5 oz.
I don't think running 16:1 with TC-W3 would be harmful, except to your wallet. It would smoke more and need decarbonizing more often. I think it would be safer than running the 30W at 16:1.
Oiling 2 stroke fuel is a lot like drinking water. A bit more than you need is generally harmless; it is not getting enough that will kill you.
Ok, thanks on and all! Special thanks to Vic! According to my calculations then, for every 4 gallons of gas I would need to add 25.6 ounces of TC-W3, correct? I picked some up at Walmart the other day. Got the best I could find but it was some ? Super tech or some such. The container said it exceeds all expectations or whatever. Shall I buy something better?
Fuel To Oil Ratio For Evinrude Fleetwin
Linear Mode
