Hello everyone. I've never posted to this group before but I have a
question that I hope you all can help me to answer.

First, a little background info. My dad has a 1991 Yamaha 3-cylinder,
85 Horsepower 2-stroke engine on his 16' boat. The boat was just loaned
out to one of my brothers for a weekend at our cabin on the lake. My
dad later remembered that he didn't mix the fuel with oil at 50:1
before handing over the keys to my brother. We managed to get in touch
with my brother and tell him to bring the boat in, but the engine was
run for about 60 to 90 minutes without the oil mixed in.

The question here is: what special care, if any, needs to be taken in
order to ensure proper operation of the engine? Should we add a thicker
oil or some sort of treatment, or just mix in oil as usual and resume
normal operation?

Thanks for any help you can provide!

-Jared

wrote:
Hello everyone. I've never posted to this group before but I have a
question that I hope you all can help me to answer.

First, a little background info. My dad has a 1991 Yamaha 3-cylinder,
85 Horsepower 2-stroke engine on his 16' boat. The boat was just loaned
out to one of my brothers for a weekend at our cabin on the lake. My
dad later remembered that he didn't mix the fuel with oil at 50:1
before handing over the keys to my brother. We managed to get in touch
with my brother and tell him to bring the boat in, but the engine was
run for about 60 to 90 minutes without the oil mixed in.

The question here is: what special care, if any, needs to be taken in
order to ensure proper operation of the engine? Should we add a thicker
oil or some sort of treatment, or just mix in oil as usual and resume
normal operation?

Thanks for any help you can provide!

-Jared


It's not oil injected?

If it ran that long, it's OK, or at least as bad as it's going to get.

There may have been enough oil in a partial tank, perhaps around 100:1,
to get you through the "oversight". Make sure all future tanks have the
proper mixture from here on out.

Rob

trainfan1 wrote:
wrote:
Hello everyone. I've never posted to this group before but I have a
question that I hope you all can help me to answer.

First, a little background info. My dad has a 1991 Yamaha 3-cylinder,
85 Horsepower 2-stroke engine on his 16' boat. The boat was just loaned
out to one of my brothers for a weekend at our cabin on the lake. My
dad later remembered that he didn't mix the fuel with oil at 50:1
before handing over the keys to my brother. We managed to get in touch
with my brother and tell him to bring the boat in, but the engine was
run for about 60 to 90 minutes without the oil mixed in.

The question here is: what special care, if any, needs to be taken in
order to ensure proper operation of the engine? Should we add a thicker
oil or some sort of treatment, or just mix in oil as usual and resume
normal operation?

Thanks for any help you can provide!

-Jared


It's not oil injected?

If it ran that long, it's OK, or at least as bad as it's going to get.

There may have been enough oil in a partial tank, perhaps around 100:1,
to get you through the "oversight". Make sure all future tanks have the
proper mixture from here on out.

Rob
It is not oil injected, unfortunately. It was filled with fuel when
completely empty, with maybe 1/2 gallon of fuel still in the tank.
We've had the boat for years, and we always mix in the oil, it
literally was just an unusual "oversight." Thanks for the reply.

Anyone else have any input? Use a different oil, use an additive, any
other ideas? Or just go ahead and run it with the usual mix and call it
good? Thanks again in advance.

-Jared

jared81 wrote:
trainfan1 wrote:
wrote:
Hello everyone. I've never posted to this group before but I have a
question that I hope you all can help me to answer.

First, a little background info. My dad has a 1991 Yamaha 3-cylinder,
85 Horsepower 2-stroke engine on his 16' boat. The boat was just loaned
out to one of my brothers for a weekend at our cabin on the lake. My
dad later remembered that he didn't mix the fuel with oil at 50:1
before handing over the keys to my brother. We managed to get in touch
with my brother and tell him to bring the boat in, but the engine was
run for about 60 to 90 minutes without the oil mixed in.

The question here is: what special care, if any, needs to be taken in
order to ensure proper operation of the engine? Should we add a thicker
oil or some sort of treatment, or just mix in oil as usual and resume
normal operation?

Thanks for any help you can provide!

-Jared


It's not oil injected?

If it ran that long, it's OK, or at least as bad as it's going to get.

There may have been enough oil in a partial tank, perhaps around 100:1,
to get you through the "oversight". Make sure all future tanks have the
proper mixture from here on out.

Rob
It is not oil injected, unfortunately. It was filled with fuel when
completely empty, with maybe 1/2 gallon of fuel still in the tank.
We've had the boat for years, and we always mix in the oil, it
literally was just an unusual "oversight." Thanks for the reply.

Anyone else have any input? Use a different oil, use an additive, any
other ideas? Or just go ahead and run it with the usual mix and call it
good? Thanks again in advance.

-Jared


Your brother may have subjected the motor to excessive wear for 60-90
minutes, but done is done. If you can find an oil additive that *truly*
restore worn out engines, see if you can buy the patent. :-)

Run it is long as it will keep going (may turn out to be a long, long
time) and replace or rebuild it when it quits.