No Oil

[O'Riley]

Johnson J15RCU
Bought new in 87
Very little use for the year.

Long story short - son put in gas within sight of shore, no oil in it. He said he ran it like
that for about 3 minutes. He had no idea it was straight gas, grabbed wrong can.

Sitting in garage now so I haven't run it. Compression seems normal when I pull the
rope, top plug and cylinder are a little white, I have no idea what to think. With the
plugs out it turns over easily by hand.

Here are some pics, top is lighter than the bottom.

Sure would appreciate any comments, this has never happened to me before
and when we have a talk he'll know better.

Thanks very much.

 

[oldboat1]

Yeah, happens. There was likely some residual mix left in the motor, and he only ran it for three minutes.

I did it with my '83 a couple of years ago -- has some trouble getting it to idle smoothly and couldn't figure it out until it struck me that the oil next to the tank was not IN the tank. It has continued to run fine. Those motors for a while were badged to run with 100:1, so have to assume they are fairly robust (recommendation back to 50:1 as I understand it because storage with the lean mix was hard on the bearings(?))

I would do the 50:1 mix and go run it (or let your son so he feels better about it).

 

[O'Riley]

Indeed, I ran 100:1 for years till reading on this forum that 50:1 was better and I switched, runs great.
Not sure how long ago that was, time does fly after retirement.

Maybe shoot some oil in the cylinder before starting or am I over worrying about this?

Again, thanks very much.

 

[oldboat1]

a little to "prime" the cylinders probably wouldn't hurt for first startup. probably just a feel good thing, but that's ok too.

(retirement time does fly by, no question...)

 

[boobie]

He most likely didn't hurt it. You could probably idle that motor all day on straight gas but don't speed it up.

 

[F_R]

Reminds me of a story I tell on myself. Fella brought in a new Lawn Boy mower (two-stroke) that he ran on raw gas. The piston was seized. So, I installed a new short block (a stripped engine). Started it up and shoved it outside to break in a bit while I did the paper work. Well it ran about 3 minutes and came to a horrible screeching halt. Dummy, I hadn't changed the fuel in the tank.

Report: The piston is the first thing to go.

 

[Silvertip]

This is exactly why so many DYI'ers rebuild an outboard that has overheated and stuck the engine or severely scored the cylinders and don't rebuild the carbs which probably caused the problem in the first place. They then wonder why the engine failed again. A friend has a Craftsman Pressure Washer that from new, he could not run for more than 1/2 hour before it would quit and not restart. I told him it is running hot and the carb needs service. He took it to Sears and they replaced the short block only to have the problem remain. I finally convinced him to drop it off and I would go through the carb. It was full of slimy green gunk and after being cleaned has run flawlessly ever since. Lean fuel means lean oil in a two stroke.

 

[O'Riley]

Thanks guys, didn't realize there were more posts here. I think I'll go out and put the motor on the stand I built then I
can run it as long as I want. I'll squirt some two cycle oil in the pistons first just to make me feel good and see what
happens.

I'll recycle the gas in the hose but the carb still has straight gas, anything I can do there? Few minutes won't matter?

Monday I'll go buy a compression tester, can someone tell me what I should get on that?

I case you haven't figured it out, I always think the worst but am usually wrong. Hope so.

Thanks

 

[oldboat1]

As soon as you prime the motor using the bulb, you will add an oil mix to what's in there. I would run it in a plastic trash can or something similar, and let it idle. Do the usual stuff -- check head temp (120 to 140F or thereabouts, if you have an IR gun). If it's too hot to touch, it's running too hot. Look for exhaust water from the bypass ports on the rear of the leg. (Flow is heavier running at speeds in the lake, but should get a decent spray running in a barrel.)

Other than adding a little cylinder lube like you suggest, I wouldn't do anything different with the mix. Adding a richer oil ratio will just foul plugs.

 

[O'Riley]

Finally had a bit over 50? so I tried it, started on first pull and sounds good to me.

All I did was spray some fogging oil in the cylinders and started it up. Only thing
wrong that I could see was a pin hole leak in the hose going to the pisser. I just
changed that hose a few years ago.


Here's a short video I took after idling for a good 20 minutes....

​Temperature on both heads was around 120?.

Looks good, yes?

Thanks

 

[racerone]

Proves once again that lubrication inside a 2 stroke is not well understood.-------My opinion.

 

[O'Riley]

Proves once again that lubrication inside a 2 stroke is not well understood.-------My opinion

I'm not sure what you mean by that but it just boggles my mind that
a shot glass of oil in a gallon of gas can lubricate your motor.

After spraying some fogging oil in I would turn it over a few times
then spray again. Should help?