Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 X-Wedge Sump Plug Thread Stripped

+1 👍

When they told me that I was surprised and figured out they did not want to admit it was something more complex, like oil seeping past the pump, so I left it alone in regards to poking the tiger that held the spare parts.

I got this out of the S&S manual.



In a completely sealed system there could be a pressure/backpressure in the tank but the minute it is open oil would flow past the pump vanes.

plugs look fine, but probably because when I take it out I will tend to drive an hour or more

Have you put a scope into the cylinders? You can easily check out the cylinder walls for scoring with an inexpensive WiFi to phone scope.

This was a quick look into the cylinders after2500 miles. The hone marks are still visible meaning that the engine is still not broken in! Needed more gentle time in my opinion.



No scoring of the walls.

Honing marks are visible over most of an engines life, say for at least the first 70%, perhaps as high as 80-90% of its nominal lifespan. On an air cooled twin like the X-wedge in the M3W I would guesstimate that lifespan at 50-60k miles unless it's mostly highway miles, in which case I would go higher.

During the break in period, which is typically very short with modern rings, the 'peaks' left behind by the honing process are quickly worn down while the (visible) grooves remain. These are an essential component of maintaining an oil film on the cylinder walls during operation. As the miles pile up, eventually the cylinders will wear smooth, blow-by will increase, and effective compression will reduce.

As an example, on my last BMW which I sold at ~185k miles, the purchaser did a comprehensive pre-sale inspection including a boroscope which still showed a visible, but fading crosshatch pattern. (synthetic oil changed every 5k).

So visible crosshatch grooves are in no way an indication of 'break-in' per se on a modern FI engine using modern oils and piston rings.


For those raised in the days of carburetors, significant bore wear (i.e. crosshatch gone) could occur well before 100K miles, as this was primarily down to the imprecision of carburetion and the resulting 'bore wash' from excess fuel during much of the running cycle. Modern Fuel Injection (FI), aided by better compression ring material and oils, have done wonders to extend engine life.

Thanks for the education Steve, constant learning is a good thing.

I know that mine does not smoke and there are not gouges in the cylinder wall and i think Roger needs to look for that. Of coarse it could be worn valve guides too.

currently I am not getting smoke at start up.... Having driving old gold wings I am certainly used to left handed oil smoke at start up

Just found my newly fitted oversized sump plug and.or washer was possibly not sealing (cue a fair amount of new oil over my garage mat / floor, oil dripping from the plug, and no obvious other leak point). Need to investigate some wire locking, but couldn't see what would be locked to where... hmmm this gives me some ideas!

Possibly a small amount of high temp silicone sealant on the adaptor threads on assembly if it is leaking from there, or a Viton O ring under the adaptor, as with the original plug? Don't over tighten it or you will be in danger of pulling the alloy case threads again.

As for wire locking, I would lock the adaptor to the oil pressure switch by drilling a hole across two flats, then that will stay locked and not require disturbing when removing the drain plug. Finally lock the drain plug to the adaptor, always "pulling' in a tightening direction.

The great thing of our M3W is experimenting.

Personally I think one of the best solutions is using a Stahlbus oil-drain as described in our bevel box project Stahlbus-drain-on-recon-bevelbox
You have them in several thread sizes so making a new bolt-thread or a coil is perfect, because it will be the last time you ever use this bolt-thread.

To protect this and the rest I made a stone guard Stone guard

see picture