I have the OS .46FX and I want to put the after-run oil inside the engine, but I dont know where to inject it.
According the the engine manual, it's said "Do not inject after-run oil into the carburetor as this may cause the O-ring inside the carburetor to deteriorate"
I'm guessing I need to remove the glow plug in inject the after-run oil in there. Is that correct?

Yikes, I always put my after run oil in the carb and turn the engine over by hand about 10 times...........haven't had a problem in over 3 years though.

The ideal way to do it is to take the plug off, and put it in the cylinder, but that's a pain.

you are correct.

i would put it into the carb as well otherwise you cannot be sure it is getting to the bearings which are the part most susceptible to nitro damage.

Like most guys, I've been shooting oil down the carb opening for years with no problems. Shooting some down the glowplug hole is a good idea as well, but I never bother with that, even when I could.

Some of it depends on what you use for after run oil. If you are using a petrolium based oil, it can attack the rubber o-rings, but there are lots of good oils out there that don't attack the rubber, or at least don't seem to. I've been using ATF for after run oil, and while I haven't actually tried soaking some O-rings in it to see if they get soft, I haven't had a problem yet.

I've been using Marvel Mystery Oil on my engines, I squirt it through the carb. Never had any problems.

I haven't ever used it in almost 30 years of flying and never worn out a bearing. There is enough oil in the fuel to take care of lubing the engine and the nitro evaporates so fast it isn't a factor. Unless you are in a real humid environment, I wouldn't worry about it, or unless you are storing it for a long time, then I use marvel too.

I bought a used OS60SF that had been in the box on the shelf for several years. When I finally decided to use it, it was pretty stiff so I filled a container with 15% fuel and just put the engine in there for about four or five days. When I pulled it out, it turned free without any binds. It now powers my Tiger 60 and runs very strong. Good engine, but, from what I could see, this was never stored with anything in it except the residual running oil that was in the fuel. That is not to say that I was not lucky nor to say that after-run oil does not help because I use it, about 6 to 10 drops after running the thing dry, put it through the carb and turn the engine over by hand a few rotations, close the carb (throttle to min with min trim) and, so far so good. Three of my engines have lasted through the winter months without any issues... that I can see, that is. I'm sure one of the backyard engineers on the forums will tell me different, though. Hey... Justin Wilson (chef and safety engineer) states that he is double safe.. both a belt AND suspenders. A tad bit of Marvel Mistery Oil never hurts.

I have been told that that the warning about the O-ring damage means don't inject after-run oil into the fuel inlet of the needle valve or carb. It is ok, in fact recommended, to put oil into the carb air inlet.

I do not think putting it in the glow-plug hole is a good idea as sooner or later you are certain to cross thread or strip the head. Also, the copper washer will eventually become so deformed that it will not seal properly.

thanks guys/gals for answering my question. You're being very helpful. Now I can safely inject the after-run oil into the carb...no worry...
I use Hobbico after-run oil. I hope this is good....

I use hobbico also.....seems to work fine for me.

I have bottle of the Hobbico too...but the man at the LHS told me he thinks it is just ATF.....
which is what he uses...

go figure!