The Middle Gear Drain Plug isn't a maintenance item.
It's there to facilitate emptying that cavity if you are going to split the cases.

Don't touch it.
Resist the urge.
There isn't a clear "Reach" to get to it.

If you break it ... and it's just sitting there waiting for you to do so ... you will be so sorry you did because there isn't any easy fix without dropping the exhaust and even moving the engine off its mounts.

There's only a third of a cup of oil in there that has already been filtered and will change itself shortly after you start the engine with a sump of clean oil.

Do not mess with the Middle Gear Drain Plug.
You do so at your own risk.
Officially, the Membership has been warned to ignore instructions not appearing in a FACTORY Manual.

Please don't touch the Middle Gear Drain Plug ... it's a Nasty NIGHTMARE if you break it and the odds are ... you probably will!

Thanks Rick,

Changed the oil but couldn't work out how to undo the bloody thing anyway! Sometimes ignorance IS bliss!

Now ya tell me...... from my other post, What is the best way to get it fixed, I have a 4-1 exhaust that doesn't get in the way, from what my local shop said, I could leave it as is and kinda seal it with silicone.... would a drill bit and easy out work

I sure am getting tired of Ricks stupid warnings! I always remove the middle plug to drain all the dirty oil when I do an oil change and haven't had any problems. I suppose you could just leave it if you were really lazy but since you're changing the oil might as well get it all.

ArizonaSteve wrote:

I sure am getting tired of Ricks stupid warnings! I always remove the middle plug to drain all the dirty oil when I do an oil change and haven't had any problems. I suppose you could just leave it if you were really lazy but since you're changing the oil might as well get it all.

The only good reason I can think of to go after this last bit of oil is if you are switching from regular to synthetic oil (for some reason). Even then, you're probably better off just doing a double oil change. (Filter change along with the second change.) That's what I'm planning to do with my bike, since the oil is likely REALLY old. PO did a lot of strange things to this bike...

Unless you already know how to get at that plug AND that it will come out, you're better off leaving it alone.

Until I found this site, I never knew the middle plug existed. I've been changing oil for 26 years on the same bike and it seems to like the care it's been given.
If you ever think to yourself, "I wonder what this does?" you probably shouldn't be touching it!

It's NOT a "Stupid Warning"
I doubt if there are such things as stupid warnings.

My writing to The Membership is the moral equivalent of placing a sign at the edge of the Pond that says:

"Danger; Thin Ice!"

You get a warning. That is the very least one should do. I know Steve doesn't agree with me and that is his right. He holds a different opinion.

But, the warning still stands. You have to determine is you are ready to face the results of your actions AFTER being warned that a situation you face has dire consequences. You don't venture out on to the ice without knowing there is a risk.

Risk.

There IS a risk. The removal of that Middle Drain Plug DOES NOT come without a very serious risk.
The risk is that you will break it off and find yourself in a calamity that has no easy solution and can easily escalate to a worst case scenario in the blink of an eye.

My responsibility and Duty to The Membership is to Post the WARNING.
I would be remiss in not doing so.

I think those Members who have attempted the removal of the Middle Drain Plug and had it snap-off for them will back me up.
It's NOT worth the risk.

A warning is the most responsible thing to do.
Any stupidity resulting from the warning will be to have been warned and carry-out the action despite being warned and wind-up falling through the ice.

RickCoMatic wrote:

It's NOT a "Stupid Warning" I doubt if there are such things as stupid warnings.

There are, but I doubt this is one of them. Don't let it bother you, Rick; Mr. Acetone here... nah. I'm not gonna say it.

Not publicly, anyway.

I love taking both sides of an argument.

On the one hand, it has been shown fairly consistently that things like the "break-in period" for engines is not only mythical, but can be harmful to an engine. Therefore, challenging non-sensical warnings is often a good idea. "Playing it safe" is a BAD idea if it really isn't safe, or worse, you don't even know WHY your method is safer.

One should NEVER squelch critical thinking either for or against a thing.

That said, I don't think that really applies in this case. The danger of breaking off the middle gear drain plug has been shown both theoretically and in practice. Combine that with the very small amount of gain to be had by pulling the plug and you get a lot of risk for very little value.

Therefore, pulling the middle gear drain plug can be pretty conclusively shown to be a Bad Idea(tm).

As always, there is an exception: If you already know how to pull it safely, then the aforementioned risk goes to almost zero. You are then left to weigh for yourself whether the small amount of gain is worth the small amount of extra effort. This applies to Steve, and he has made his choice to go ahead and drain it. For him, the warning only serves as a reminder that his case is the exception. IT MAY OR MAY NOT APPLY TO YOU.

MY MAIN POINT: The critical point is YOUR EVALUATION of your ability to pull that plug safely. Just BE AWARE, make good decisions, and BE PREPARED for things to go south.

A warning is not a Rule That Must Be Followed Or Else. It's just an attempt to convey information based on the author's knowledge and experience along with a sense of urgency because it is meant to protect you. You are still free to heed it, or not.

I heed the middle drain plug warning and leave it in.
I change my oil filter every OTHER oil change (usually).
I re-use O-rings and spark plugs, unless they are actually worn.
I leave the battery on the bike when charging it.
I have never once put Stabil in my gasoline.

You pays your money and you takes your chances.

Well the XJ Gods were watching over me, went to scrape RTV Sealent that I was told would work, still dripped a bit, and to get ready to seal the hole for good, well when I put the flat tip screw driver in to finish getting the sealent out, the what was left of the bolt move, so it's out and a new one going in with a big note not to touch

I think what Rick is referring to here is the "Fuuuuuuuudge!" factor. And everyone who has seen Ralphie in "A Christmas Story" knows what I mean.
If you feel comfortable removing the middle plug (Arizona Steve obviously does!) go for it. If he's removed it before, he knows how and it's not seized. I think Rick is targeting the new-to-oil-changers who might be contemplating removing a seized plug that hasn't been removed in 30-something years. I agree; bad idea. Unless you're willing to pay the piper should the need arise. My XJ is a 550 so I don't have to worry about it. But I'd rather someone warn me about it beforehand than razz me about it later.......just my .02

Thank you Captainkirk.

The problem is that it is referred too as Maintenance in the HAYNES.

It is NOT cited in the YAMAHA Factory Manual.

Someone acquiring an old XJ-Bike and wanting to do some maintenance might think it is necessary to drain that cavity during a routine oil change.

If they do, having read about it in the HAYNES will draw their attention to that Drain Plug and we're likely to have another victim of mis-information!

I give the warnings that people need to prevent them from sliding into a black hole of despair for doing something that ill advised ... and, in the case of changing the oil in the Middle Gear cavity ... unnecessary.

It is NOT necessary to change the oil in the Middle Gear Cavity.
It changes itself shortly after you start the engine with clean oil in the sump.
Since there isn't enough oil in there to cover a stack of pancakes ...
Leave the Drain Plug alone.
Forget about it.
Do something else.
Don't deliberately cause yourself some heartache because someone happens to disagree with me.

There are some people in this world that are made to disagree with everything you say or do.

You could be standing in the sun, at the foot of Big Ben, listening to it chime 12 times and they won't acknowledge it's Noon.
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Just because they say it's OK and you should go ahead and do it ... does not mean they are going to come and help you fix the problem if you are swayed by their dissent and wind-up in the fix I am trying to help you avoid!

I'll agree with Rick on this whole subject, Mine is easier to get to since I have a 4-1 exhaust, but after this weeks saved my bacon experiance, I'm not touching it again. infact when I put the new bolt in (8mm 1.25 pitch approx 12mm length), I added a little RTV sealeant to the washer, this way If I have a plate of Dumb A$$, and go to change it, I'll think twice. It's just not worth the headache it could have been for a 1/4 to a 1/3 of a 20oz soda bottle of Oil. (My .02 Cents...........what you mean here's my .03 Cents in Change)

The owner's manual was included in my purchase of an '81 XJ650H and not knowing any better I followed the oil change instruction in it to the letter. The owner's manual does say to remove the middle gear drain plug and fortunately, everything went fine for me. I noticed that very little oil drained from it, so it seemed almost not worth the effort.

So far I have been lucky with stuck fasteners. The oil filter housing bolt on my bike must have been tightened with an air impact wrench. I think the cloud of profanity that caused still lingers above my garage.

I've removed the plug for the past few changes... every single time I do it it takes me a while to find the damn thing, even more to get a grip on it and pull it.

BTW the only reason I ever found out about the plug is from a post on THIS SITE saying it was good to drain it... and no red flags were shot up at that time (otherwise I wouldn't have bothered).

Anyway, I'm not gonna do it anymore - no big difference. I'll pull it if/when I pull the motor.