How Long Can a 2 Stroke Run Without oil

[GWMASON]

I always add my oil before adding gas, but somehow yesterday I forgot one of my tanks was pure gas. I have a 1989 Johnson 140 hp 2 stroke. It ran for a while and then would stall and start up again - I estimate I burnt about a gallon. I then checked the fuel filter and you can guess what I thought when the gas was clear. I flushed out the gas and switched tanks. I took it easy and eventually up to high throttle for a half hour or so. It seems to run fine and the compression this am was the same as it has been for years, at 107 to 120. I don't notice any difference in sound that might be bearings. Could I be so lucky as to run that long on straight gas with no obvious damage?<br /> <br />Thanks<br /> <br />George

 

[Silvertip]

Re: How Long Can a 2 Stroke Run Without oil

Only time will tell how lucky or unlucky you are/were. It appears you dodged a bullet however.

 

[tiller7104]

Re: How Long Can a 2 Stroke Run Without oil

"How long can a 2 stroke run without oil" LOL about as long as it will take you to right a check for $1800 LOL Sounds like lucked out big time. I have seen engines run on straight gas for about 3 minutes and lock up! Your compression may have been 107 and 120 for a long time but that is quite a difference? The rule of thumb I have always heard is no greater than 10% difference. Hey what ever works! Good luck and keep the oil flowing!

 

[seahorse5]

Re: How Long Can a 2 Stroke Run Without oil

In testing I've run large engines at idle on straight gas for over 2 hours without problems. When power is applied, such as getting up on plane, a motor will be seized or internally damaged in a very short time.<br /><br />Check compression first and/or pull the heads and inspect the cylinder walls.<br /><br />I take it that the VRO system is disconnected and that is why your are mixing the gas and oil.<br /><br />Over the years I've seen perhaps 10 times the number of ruined motors from folks disconnecting the VRO and forgetting to mix the oil, as have ever been damaged by a faulty VRO pump.

 

[tashasdaddy]

Re: How Long Can a 2 Stroke Run Without oil

during hurricane season i fill all my tanks with plain gas, and put red tags on them. this is a waring tag that there is no oil. i do this as i have 4 6 gal tanks and 5 standard 5 gal cans for gererator fuel. go boating you just add oil a tank at a time and go down a bumpy road.

 

[GWMASON]

Re: How Long Can a 2 Stroke Run Without oil

Originally posted by seahorse:<br /> In testing I've run large engines at idle on straight gas for over 2 hours without problems. When power is applied, such as getting up on plane, a motor will be seized or internally damaged in a very short time.<br /><br />Check compression first and/or pull the heads and inspect the cylinder walls.<br /><br />I take it that the VRO system is disconnected and that is why your are mixing the gas and oil.<br /><br />Over the years I've seen perhaps 10 times the number of ruined motors from folks disconnecting the VRO and forgetting to mix the oil, as have ever been damaged by a faulty VRO pump.

 

[GWMASON]

Re: How Long Can a 2 Stroke Run Without oil

Originally posted by seahorse:<br /> In testing I've run large engines at idle on straight gas for over 2 hours without problems. When power is applied, such as getting up on plane, a motor will be seized or internally damaged in a very short time.<br /><br />Check compression first and/or pull the heads and inspect the cylinder walls.<br /><br />I take it that the VRO system is disconnected and that is why your are mixing the gas and oil.<br /><br />Over the years I've seen perhaps 10 times the number of ruined motors from folks disconnecting the VRO and forgetting to mix the oil, as have ever been damaged by a faulty VRO pump.

 

[GWMASON]

Re: How Long Can a 2 Stroke Run Without oil

You are correct - the VRO was disconnected when I got the boat several years ago and I was advised not to reconnect since there was some risk it was disconnected for a reason.<br /><br />The compression still ranges from 107 to 120 in the cyclinders which is less than ideal but the same as it has been for the several years I have had the boat.<br /><br />I have no loss of power but remain concerned about "hidden" damage.

 

[dakotarmx]

Re: How Long Can a 2 Stroke Run Without oil

wow you got lucky .suprized it didnt seeze on you .if youre compression good and it runs fine .roll with it .you got a free pass

 

[dakotarmx]

Re: How Long Can a 2 Stroke Run Without oil

if it aint broke dont fix it