OK to use 2 cycle oil in a four stroke?

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I fail to see the point. A well-built, well-maintained automotive engine will run 200,000 miles without any oil in the gas. What would you expect to improve? OTOH, I could imagine a lot of carbon buildup in the cylinders and on the valves, not to mention the potential damage to the cats, by adding oil that's not supposed to be there.

All in all, it's not such a great idea.
 
I have used two-cycle oil in 4 cycle engines and I say don't because of the added carbon build up on the piston, head, vavles and sparkplug. Four stroke engines were designed to be run on plain gas and are just fine with that. If you do run two cycle oil in your 4 cycle make sure you use tcw3 ashless oil to reduce the deposits.
 
I have, (when getting rid of old mix) and wouldn't use nothing other then MMO in the gas of a 4 stroke mower..
 
I was just wondering about using the 2 cycle oil as I use my push mower with a 4 hp Tecumseh engine on a small bank near our road. I just want to make sure it is getting enough lubrication.
 
If the bank is too steep, all its gonna do is lube the cylinder walls... it in no way is gonna lube the inside, and when the oil gets away from the slinger, and the slinger can't get the oil to throw it around in proper amounts... then your rod and crank, not to mention the cam won't get lubed good.... kinda is like running em a little low on oil... even though its full.
 
Would it be beneficial to a four stroke engine to run synthetic 2 cycle oil at a 100:1 mix? Wouldn't this help lubricate the cylinder walls and upper end? Is there a downside to using the 2 cycle oil? I have both Poulan and Mobil 2T synthetic oil. It seems my 2 cycle engines run better on the Mobil oil.
 
I always run 32:1 in my lawn mower. I have a little mower with a 3.5 HP Briggs engine. Been using the mix for two years now with no issues. Reason being I have a small yard and only use about a gallon of fuel every two months between my mower and 2-cycle trimmer. It's a whole lot easier than keeping two seperate fuel supplies. Also, the plug is clean!
 
2t oil can be used in 4 stroke engines in small quantities with some benefit. Certain engines are prone to problems and high rates of wear. Those are more likely to benefit from the addition of a tiny amount of 2 stroke oil. Old engines with sticky valves for instance. This is a common trick on lycoming engines run on 100LL, it frees up the sticky valves.

It can also reduce the load on the valve seat due to excessive RPM. Very high rates of valve closure can pound a seat into an alum head. 2t oil may help a little according to some.

Remember that some gasoline has lubricity addtives already.

Chris
 
I run amsoil 100:1 2 stroke oil for all my 2 stroke equipment. I use this same gas for my dethaching mower, roto-tiller, and pressure washer. I have evan added it to my atv in a pintch. I have never had any problems with any of the 4 stroke equipment or 2 stroke for that matter. I would think it may help a little bit but to much may carbon it up some.
 
I have used this on occasion at about a 100:1 mix with no ill effects and no smoke either. Usually I'm just wanting to mix up a new batch of trimmer gas and getting rid of the year old stuff. I would mix it lean at 100:1 to get some benefit, but still keep things clean. I've also been using the 100:1 Amsoil premix for my saws and trimmers and have been satisfied with the improved performance of these engines using this stuff. I also like Mobil MX2t at 50:1 in these aircooled engines.
 
Also keep in mind that 2t oil keeps gas fresh for a very long time. Mixed at 32 to 1 I have had dirt bike tanks last for 2 years and still be fresh.

Chris
 
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