Magnetic drain plug

It isn't in need of a crush washer. The gearbox doesn't have a gasket and is basically metal to metal. Yes it does have some Loctite 598, but no gasket. Several other bolts and don't have crush washers either. It works and has been working for a couple of decades and hasn't been an issue. The one thing Rotax did was get rid of the #40 Torx head mag plug and went to a 16mm hex head plug. Now that was a good idea.

Hi Roger

No disagreement with anything you've said, but it doesn't answer the question of whether there is any reason not to use a crush washer - which would solve the well known problem of undoing the plug and the outrageous cost of a new one.

You've posted tips yourself about using grips on the plug, and slotting it with a Dremel, others suggest heating the casing, chilling the plug, hitting it with a drift, even using an easy out. You know the problem. Why accept it if it's avoidable?

If I can buy a hex head titanium plug for a racing motorcycle, with wirelocking provision as required for track use, for £12 against Rotax's £70, is using a crush washer any detriment? Bike racers aren't going to use rubbish plugs that lose their magnets.

Mike

"which would solve the well known problem of undoing the plug and the outrageous cost of a new one".

There was an issue with the older Torx head plug because the head would strip out way too often, but if you have the newer style 16mm hex head one that has been out for many years there is zero issue with removing or installing it and neither plug ever leaked.

The Dremel and removal issue was only with the Torx head model after you stripped out the head..  Everyone should have the 16mm hex head and get rid of that old Torx head. I just take a 3/8" socket wrench, put a standard 16mm length socket on it and break it lose or tighten it. It's very easy and quick.

Personally I wouldnt try to adapt after market parts. You may face some severe engine issues if something fails. No one said owning an aircraft is cheap. It takes due diligence and money to support your dreams.

Well, we have been using a motorcycle magnetic plug with a washer for more then 7 years now. Guess what, the engine never complaint. You are on the right track. It has served the purpose perfectly and will, most likely, continue to do so.

I have been using a "copper washer" on the magnetic plug, for years - may not be necessary but makes me feel good.