I'm diagnosing a heavy smoking issue with my 3EN1, which was found on cylinder 3. The header and exhaust port are wet with oil, so that made me think of the piston, cylinder and/or piston rings. It also has light smoking on the crankcase breather hose. I pulled the carbs out to check valve stem seals, and I saw one with some wetness coming from the stem, which can signal stem seal failure. Highly likely since most 'mechanics' here would not replace them if you won't tell them

Before I got this bike it had the piston rings replaced and probably a valve re-grind and cylinder hone. Since I see some goop on the mating areas that tells me the gaskets were reused. That was at least 8 years ago.

Now, to further clear up where the issue is, I have to check cylinder 3(because that was the only cylinder giving me the smokes) and all other cylinders are
fine, which requires pulling the head and cylinder block off the engine. I do feel bad reusing the gaskets since I don't do that myself, but with a tighty budget I might have to. Would it be OK or not?

{More information on the smoking, it does not smoke much when newly started up; only starts to smoke up when the revs are raised and won't stop from there}

Head gaskets aren't that costly to replace, the old one is probably going to end up getting damaging when you pull the head off.
I think most on here would tell you to replace with a new one. How annoyed would you be if after pulling it apart, spending all that time fixing it then rebuilding it to finding out the gasket you reused to save a few quid is now leaking. Meaning you have to now pull it apart again just to replace a part you should have replaced before.
Please don't cut corners and learn the hard way.

I said I won't, but with budget issues(a chap got into some accident and had surgery) it's an option for last resort until a proper cure can be used

Wonder about availability. If it was a 750 or 1000 I can easily have a set since I worked on those for years, and I cannot rely on online products since I can only pay cash (probably go Amazon to use Western Union perhaps?) Some dealers might still have them but I should not hope on that

By the way, I said that the gasket was previously reused. They just put some gasket cement and that's not how I do things, it feels dirty and insulting...

I never said you had reused the old one using gasket sealer to seal it only it isn't worth doing it, as if it doesn't seal it has to be pulled apart once more. I've never owned a Yamaha so cannot comment on the availability of parts. Maybe the previous owner used gasket sealer as he struggled to find the proper gasket.
Does cmsnl.com not have them in stock?

The bike is a 3EN1, so a 1WG gasket set, same as with the US SW/SA (SWC/SAC)

They have stock on the head gasket, also says superseeded by the 3TJ part, same exact price, the base gasket is a 3TJ part, also available. But looking at payment methods I cannot order there, and I'm not in Europe as well

Would the aftermarket ones (Athena, etc) can be okay? I do know that OEM is better than most...

I have a friend who used many Athena gaskets on his rgv250 vj22 around 12 months ago with no problems.
I would also say id prefer oe gaskets over aftermarket ones but i presume at some point the original manufacturers are going to stop making them so we all would have to purchase aftermarket ones, there are always going to be better quality aftermarket ones than others. That's were the problems may start by trying to find out which are the best.
If you are thinking of purchasing the Athena ones ask around first. I think evilchicken from this very forum has a 3TJ. Failing that try pbmagforum as he's also on there

Also i apologise as i thought you were based in the UK

I try to use one head and base gaskets but having looked at both the one and Athena I could see a difference.

Get a wet / dry compression test this doesnt sound like valve stem seals.
Always use new gaskets

Sorry for being away, just dissected a Yamaha scooter for damage assessment and an issue with internet connections

So I should hunt down the OEM ones? Or the Athena set can do? Or another brand?

Regarding compression test, I will try that when I can get my hands on a tester. I cannot move around yet with the quarantine, better be safe than sorry

If all you're doing is the top end then it's probably cheaper to buy individual gaskets which will probably be genuine because theyll be cheaper than a set.
If you're going to do the clutch and / paint the covers might be cheaper to get set - do your sums