I have a early 70's Johnson outboard motor. I mixed the fuel/oil ratio with too much oil.Will this hurt it?

Question

I have a early 70's (model 40EL75C) Johnson outboard motor. I mixed the fuel/oil ratio with too much oil (50:1) and ran it about 2 hours that way and it started to miss and stall. Will this hurt anything? How can I fix this myself?

Answer 1

If you have to make a mistake on the ratio you made it in the right direction. Too much oil will not hurt the engine a bit. It may foul the plugs and it may smoke like a freight train and it might even leave some extra oil around the rings or somewhere else. Since it was missing the plugs are almost certainly the problem. I would suggest replacing them and use the correct mixture. Anything you did to the rings or any other parts will soon be washed clean by the leaner mixture.

Happy boating and don't give this a second thought. If your engine dies it is not because of two hours operation with a rich fuel mixture.

Answer 2

That old 40 will run on less oil mix cut back or add a little more gas to the mix . Change the plugs if the you can go up 1 heat range You went over 50 to 1 like if you had 1 gal left in the tank an put 50 to 1 an added 5 gal for 6 your at 40 something oil mix won't run with that an if you do this a couple of time your really off on the mix???I run all mine for yrs on 100 to1 can't stand all the smoke had no problems an plugs last for ever. All the newer eng are 100 to1. Your call ??

Answer 3

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RE:
I have a early 70's Johnson outboard motor. I mixed the fuel/oil ratio with too much oil.Will this hurt it?
I have a early 70's (model 40EL75C) Johnson outboard motor. I mixed the fuel/oil ratio with too much oil (50:1) and ran it about 2 hours that way and it started to miss and stall. Will this hurt anything? How can I fix this myself?

Answer 4

It can, under extreme oil concentrations, according to my outboard motor repair guy. He says that contrary to expectation, fuel with extra oil in it burns hotter than the regular mix. If it is way hotter for quite some time, it can warp or otherwise damage things. It is easy to correct a too-oily mistake by simply adding more gas to reach the correct 50:1 ratio. A little extra oil will not hurt a thing, but a lot might.

Answer 5

I am not an expert, but have had experience with older outboard motors and other 2 strokes.

The engine running ruff is a natural outcome of improper fuel mixture. It shouldn't hurt the motor itself. You should drain the remaining fuel, pull and clean the spark plug, run it for a few minutes with the proper fuel, then pull and clean the plug again.

Answer 6

Outboard Oil

Answer 7

Whtch out for RANGO, his mechanic friend putting 50:1 mixture in every thing , is so out dated,

I have 2 cycle engines, Some take 24:1. some 50:1 some 100:1 and some are oil injected, = no mixing at all

Answer 8

If you think 50:1 is too much, b prepared to buy a new power head.
Running less than 50:1 (one pint (16 oz.) tcw-3 two-cycle oil per 6 gallons of gas) will ruin your engine.
Check for water in the carburetor bowls & check for fouled plugs.

Answer 9

50:1 is a perfect ratio.
A friend of mine who is a mechanic says everythign leaving his shop is filled with 50:1, chainsaws, boatmotors, snowmobiles, anything that requires a premix fuel.
Running too rich wont hurt anything except the spark plugs, they will foul a bit prematurely.
If it way too rich, say 10:1 you might hurt somthing, remember oil runs at a hotter temp than gas.
I doubt seriously if you hurt anything, change the plugs and you will be ok.

Answer 10

It shouldn't heart it. Drain the fuel and use the proper mixture. You might also have to clean the fuel filter and spark plugs (they are covered with too much oil.)