Running 4t oil in place of 2t oil

Has anybody ever accidently put 4t not 2t oil in the fuel by accident?

I'll explain. I lent my brother my RM250 for him to ride around the farm now its the summer and when I dropped it off I gave him an almost full bottle of what I thought was Castrol 2t oil. He managed to run two full tanks through it before I realised that the 2t oil was still in my shed and that I had actually given him the bottle of GPS 4t, which believe it or not has red contents too!

I've stripped the top end down and it doesn't appear to have worn significantly more than i'd expect, nor does there appear to be any more build up of carbon than usual. The carb is also clean and it hasn't just settled out in the tank either.

Any thoughts on lasting damage, compromised seals etc? It is oil after all but I don't really want to risk any major damage.

Cheers

I dont think it's as much the quality of the lubricant, but the amount. running any oil is better than running no oil...

But, I would probably do a compression check, and probably do a piston fairly soon. chances are if it looks OK and it isn't due for major maintenance already, the damage isn't severe enough to lose sleep over.

No, I've never done that though lol... thought about it. Think about it, only 1/33 or 1/40 or whatever your ratio, is actually oil, so the engine isn't soaked in oil like most of a 4 stroke is (not soaked, but lubricated well) so you're probably fine

Can't be as bad as running 4-stroke gas in it...

2-stroke oil wasn't invented untill years after the motor was. motor oil was used in the beginning. Sure, 2-stroke oil of today is better, but it probably didn't hurt anything.

Like JB said, you can allways do a compression check to make yourself feel better.

I've heard or people running SAE30 in a 2stroke just to get home.

2 stroke oil has addatives that help it mix with gas and it burns clean.......For the most part.

4 stroke oil is not designed to burn. It leaves lots of carbon when it does.

I know people that use fourstroke oil for premix in their chainsaws and weed-eaters and stuff. It isn't the best option, and I wouldn't use it a lot, but one time, assuming that there was a fair amount of it in the gas, probably won't hurt anything.

i found an old bottle of Kawasaki 2 stroke oil at the shop i worked at and it said right on the bottle SAE 30 wt , im sure your bike is fine any oil is better then no oil

Don't worry at all.

The only difference is 2 stroke oil burns cleaner. Boat oil is the same as motorcycle oil now. They are both water cooled.

Don

Has anybody ever accidently put 4t not 2t oil in the fuel by accident?

I'll explain. I lent my brother my RM250 for him to ride around the farm now its the summer and when I dropped it off I gave him an almost full bottle of what I thought was Castrol 2t oil. He managed to run two full tanks through it before I realised that the 2t oil was still in my shed and that I had actually given him the bottle of GPS 4t, which believe it or not has red contents too!

I've stripped the top end down and it doesn't appear to have worn significantly more than i'd expect, nor does there appear to be any more build up of carbon than usual. The carb is also clean and it hasn't just settled out in the tank either.

Any thoughts on lasting damage, compromised seals etc? It is oil after all but I don't really want to risk any major damage.

Cheers

Hey lastchance; if you've already taken a look at your top end and it looks good and the bike seems to be running reasonably well then I'm going with the "you're golden and dodged a bullet" answer. I would change out the gas and run some nice pre-mix through the bike but I'm betting everything is fine. :worthy: N-edge

Don't worry!

I had to use car oil to get home once in an air cooled 2T dirt bike, rode 50 miles on hiways without problems.

When I was 14, on my QT50, heading out to a friends farm house about 8 mi away. The motor started to lock up. Stop and let it cool down about 3 times. The only oil he had was 15w40 diesel oil. Put some in the oil tank and some more in the gas just to be safe.

Had a tail wind, so maybe doing like 40mph:smirk: . On the side of a 2 lane highway. More smoke than a old Mack truck. I made it home with out the spark plug giving out.

The only thing I had to do after was clean all the carbon out of the pipe.

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