Fuel Mixture Ran a whole tank of gas with practically no oil by mistake!

[motorpsycho]

doing this has the same results as if you drained all of the oil out of your car engine and drove the car.
NO lubrication spells death.
it's only a matter of time before it dies....Oil in the gas now will not fix the damage that's already been done.
a bearing will lock up or come apart soon.

 

[Greg58]

The opening post States that he added straight gas to the mix already in the tank, he said the tank had about 10% mixed fuel in it. If the engiine has run this long the damage to the bottom end may be minor. Like I posted before I would run a leaner fuel ratio, and have a back up plan if it dies.

 

[motorpsycho]

The opening post States that he added straight gas to the mix already in the tank, he said the tank had about 10% mixed fuel in it. If the engiine has run this long the damage to the bottom end may be minor. Like I posted before I would run a leaner fuel ratio, and have a back up plan if it dies.

so you think that the little oil that he had in it, along with diluting that with straight gas is ok?
what little oil that was in the gas mix was not enough to lube the bearings (if it was 10% and he topped it off with straight has).
sure there was oil present, but not enough to protect anything.
if you think it'll be fine, run your engine at 100:1 mix for awhile and see how long it lasts.

 

[Greg58]

What I said was run it, if it were mine that's what I would do. Since I don't rely on either of my bikes for transportation to work the worst thing that could happen is I'd have to peddle back home or to where I parked my truck. Riding one of these motorized bikes is kinda like driving my old flat head ford, it runs great today and tomorrow it might not start. I didn't want to recommend he use a leaner mix, the added oil may delay its failure. The auto correct feature on my tablet changes my spelling sometimes.

 

[Greg58]

As for running a 100/1 mix a lot of people run opti-2 at 100/1. I have run both of mine at 70/1 with it.

 

[Ludwig II]

Modern 2 stroke oils are pretty ****ed good. Also, a slighlty less viscous fuel mix would have meant fractionally more fuel in the fuel/air mix, running the engine a touch cooler. I'd seriously consider getting a new engine and sticking it in a carrier on the bike with some spanners and just ride until the old one breaks.

 

[relaxxx]

I'm definitely going to run it until it dies. I'm just trying to get an idea of what to expect. I've gone back to my 40:1 mix. No major issues except my exhaust gasket let go on my last ride. I was like WTF is this new noise, had a look and there's black oil all over the front of the motor under the pipe now.

 

[relaxxx]

After 10-15 minutes it started making a bad noise again. It sounds like a hammer drill. Sound goes away again after a while.

I managed to record a video of the sound:

http://www.youtube.com/watch?v=cmhOwU7irCk

 

[Ludwig II]

I don't know what the US term is, but in Britain, that is your big end bearing (the one at the bottom end of the rod) saying goodbye.

 

[Greg58]

The strange thing about the sound is its very rhythmic, and you say it comes and goes. That sounds like a ring or piston problem that hits every stroke of the piston. Every rod bearing or wrist pin that I've had go bad made a off rhythm sound due to the rod moving around on the crank or pin.