How about this......

I rode to the Honda dealers for an MOT, when I stopped outside oil was coming out of gearbox breather.....WTF. The oil has just been changed and filled until it stopped draining out of level screw hole.

The level screw was removed and at least 100cc of oil came out and all is now fine, now why is that.

So next bike, rode it 6 miles and checked gearbox oil level, oil was again starting to come out of breather, same 100cc minimum came out again.

So checked next bike with cold engine and same again.

The gearbox oils were changed with bikes on a bike stand and bikes were level, must be something I did wrong, but how

How long are you leaving between draining off the old oil and refilling with new?
I generally leave the oil to drain down overnight,this is best done when the engine has been run. [ leaving a note on the tank to remind me there's no oil in the gearbox.
I then refill with 650 ml of new oil.
Mike

I just drained for 10 minutes, then refilled till oil came out of hole.............now I see where I went wrong, should have let it drain for longer at oil level hole.

But I have also drained car engine oil, filled engine up, only to find it still draining as I forgot to put drain plug back in, now I only do car oil changes by the suction method, quick and clean.

I had this problem and discovered it was the seal on the oil pump had gone so the 2T oil was draining into the gearbox.
I discovered it when i filled up the 2T to go out for a ride (as i always do) but never got round to going. It was another 2 weeks before i went out and when i looked at the 2T oil level it had dropped quite a lot. I then undone the gearbox oil level screw and a load of oil came out.

I should point out i've got a MK2, i guess the AR has the same pump set-up?

If you do find it is this it's quite a simple fix.

Cheers
Mark

I second that oil seal on the pump. I had the same problem when I first got my MK1.

^^^^^ Yes,that can be a problem, but I think in this case the error tends more towards my description.
Yes, I'm also now a fan of the " Pella" type of vacuum oil drainers.
As a test, on the wife's civic I drained the sump using the pella, then popped the drain nut off, there was not enough old oil in there to fill and egg cup, so they are pretty thorough.
A similar device for the oil filter would be a bonus, as they always create an oil slick down the casing when being changed.
If I was brave I'd punch a hole in the bottom of the filter first, but knowing my propensity for grabbing the sheity end of the stick that plan would go pear shaped.
The pella works on the TTR as well, I can drain the sump, and the reservoir tank, just allowing the last trickle out of the side drain down plug.
Mike

No 2 stoke oil is going missing, its pure gearbox oil that I am draining, and all 5 bikes gearboxes were overfull.

The Pela system is superb, I also use it for bleeding brakes on bikes and cars.