Drain plug size?

Anyone know the drain plug thread size on a 72 750. I saw on a BSA board where a guy was installing one of these.
http://www.qwikvalve.com/fumoto-f-109-v ... 16154.html
It was in an aftermarket sump plate that use a 12mm metric. I have the same plate on my 70 Thunderbolt and am thinking about getting one. Would sure make it a lot easier to drain the sump when it has sat for a while, also less wear and tear on the threads. They have a link to their sizes. Hope one might fit a Commando.

With a 12mm thread, it could only be made to fit into the large sump plug on a Commando,
it won't fit as is. And the large sizes don't go up large enough (?).

(Do all Commandos have that large sump plug ? )
(The recent thread here about these didn't establish that ?).

That lever looks dangerous, hanging down below the motor like that.
It would have to be protected, so that road debris or a rock couldn't drain your sump on the move !!

On my Land Rover I have one of these....

Its a lot less likely to open accidentally than the lever tap type...you need to take off the covering cap and screw in the hose adapter before it flows. Which is great because on the Land Rover I already have the end of the hose adapter inserted into a plastic can I use to collect the old oil....no mess at all.....except when I take the oil filter off.....which would be exactly the same with the type.

http://www.difflock.com/drain-plug-1-2-x-14-bsp

Other sizes here.... from 12mm http://www.drainplug.co.uk/standard.html

At 1/2" BSP he thread size is the same as the oil drain on my 'oil in frame' Rickman frame.... so I considered using one, and for road use I would, but for racing there would be too many issues with the requirements for wire locking.

Most of the oil is in the tank anyway, so really what you are trying to get is a 'wet sump drain tap'......

Rohan said:

That lever looks dangerous, hanging down below the motor like that.
It would have to be protected, so that road debris or a rock couldn't drain your sump on the move !!

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I thought the same thing until, under the microscope, this image shows the valve in its open position, and you have to lift the spring-loaded level up and over a step before it will swivel down into its open position.


The large sump plug on my '74 could probably be drilled and tapped to accept this valve.

Nathan

According to the link to thread sizes posted above they are available in many sizes and threads including BSP and UNC - so does anyone know the thread size for the drain hole in a 74 crank? A wet sump drain is exactly what I want!

What ever you wet sump worry warts fit, don't ever forget its sticking out down there if loading into trailers or truck lips or crossing thick grass that piles up for rather strong drag. A drain valve and tap off the back lower TS cover would be safer and easier to access and would leave some effective wet sump for the 1st few turns starting. On the few Cdo that don't wet sump much or those that don't sit long enough to wet sump much a compact drain and sight tube off oil tank drain worked a treat on monitoring wet sump oil tank level and tool-less mess-less oil changes.

3/8 unc. Nothing wrong with starting the bike once a week though, or fitting a ball valve in your supply line like I have done. The man is right that suggests it is a bad idea, because it will stick down too far. I have grounded my bike several times when putting on the back of my truck, and when it happens, it hits really hard and can jam.. I once lost my rear brake switch because I could not avoid a larger object on the road. Think about it.
Dereck

Please NOTE: Jim Comstock and a hand full of others have ruined new and old engines by just turning over now and then cold or weekly starts that were not allowed to reach full oil heat which takes a long time if not under road load fuel use conditions. Dereck has a good point on anything hanging below frame rails being way worse issue once in a while than anything always bad full wet sump can do.

Please NOTE: Jim Comstock and a hand full of others have ruined new and old engines by just turning over now and then cold or weekly starts that were not allowed to reach full oil heat which takes a long time if not under road load fuel use conditions

Click to expand...

wow, so our own highly respected Jim has "ruined new and old engines" ?

I read this forum all the time and must have missed this admission of ruination by Jim

please tell me more, Hobot, of how Jim ruined motors and also how you personally know about this

Don't you guys know what a bed is. It lunch time here. Past pumpkin time over there. Heck Hobot, you trying to scare the SOOM.
I know cold running is the worst time for an engine. I do see your point though.
Dereck