Sq 4 MK II massive oil leak

[pauldridge]

I just got delivery of my new (to me) '53 Sq 4 last week. The transport driver mentioned that the bike had leaked oil all over the floor of his rig, and then while the bike was sitting in my garage waiting for a new petcock, there was a pretty decent puddle left under the bike.

according to the seller, it has been at least 2 years since he last started the bike, but he claims to have completely rebuilt the engine prior to that (and provided stacks of invoices from Draganfly as evidence)

today, after checking points, timing, valve clearances, removing the carb and ultrasonically cleaning it, removing the tank and flushing, I went to change the oil.. I expected there would have been some wet sumping, and did find the oil tank to be at only about 1/4 full, but after a cursory inspection underneath, I could find any sort of sump drain plug.... Is there one? Or do you just have to remove that entire 4-bolt sump cover?

I decided instead to just cautiously fill the tank to about 1/2 or so for an exploratory startup.

Before I started it, but after topping up the oil tank, I noticed a fresh and growing puddle of oil underneath, but ignored it for the moment.

To my great surprise, after some 7-8 kicks, the old gal roared to life, seemed to be running on all 4, nice and smooth, good throttle response, and I quickly checked inside the oil tank to confirm I was getting return oil.

I ran the bike for only a minute or so, then shut it down, but then noticed a huge puddle of oil, and still coming out in a fairly small but steady stream.. it appeared to be coming from the bottom of the primary case, but then I had the bike on the side stand, so it could have drained from the other side.

Checking the oil tank, the level was back down from 1/2 to about 1/4 full, so I'm thinking the oil is coming from the engine, not the gearbox.

I'm still a rank novice as far as understanding the oil piping for this engine, and there doesn't seem to be any diagram showing that. I am hoping that perhaps I just have a leaking hose or line going from or coming to the tank, but nothing was readily apparent. It was the end of the day, hot and sweaty in my 100 degree F garage, so I gave up without any further investigation, hoping someone on the forum might have some suggestions as to where all my oil is going? (and, how to drain the sump!)

Phil

[nevhunter]

IF you have oil pressure indication keep running it on no load, and see if the oil gets back to the tank. If the engine has a large amount of oil in it, it will probably put it out of the breather.CHECK oil pressure. Nev

[greg.geonetta]

You have to remove the 4 bolt plate to drain the sump. After you get it off, drill and tap for a drain plug

Sounds like it wet sumped from sitting so long.

[simon.holyfield]

You have to remove the 4 bolt plate to drain the sump. After you get it off, drill and tap for a drain plug

Sounds like it wet sumped from sitting so long.

Drags have a version of that plate fitted with a magnetic sump plug.

[Bob.Murphy]

As I recall from my '53 4G (it was a long time ago ), the oil pipe that goes to the pressure gauge is soldered alongside the pipe that feeds the rocker box. I would check that both are sound (particularly if original) as a crack would give you a serious oil leak.

I had a copper breather tube, mounted on the oil pump in the timing case, that took the vapour from the centre of the timing chest through the breather hole at the back. It prevented oil draining down the walls from being blown straight out.

Bob.

[pauldridge]

Thanks for all those useful suggestions. I am going to go with the wet-sumping idea first.

Sorry to be so ignorant, but where exactly does the crank vent exit the engine?
Phil

[roger.fellows]

A copper pipe originating from the inboard upper part of the timing case and below the shelf under the dynamo. Very difficult to see when bike is in one piece.

[roger.fellows]

Do you have a morgo pump fitted? If you search for timing chain you will find quite a few threads including some photos which will give you a better idea.

[paul.jameson]

I would recommend removing the timing cover - which is simple enough - just remove the screws. You may have a Morgo pump fitted - which will say Morgo on it or you may have the original pump which is drive by a skew gear from the end of the camshaft. The morgo pump covers the end of the camshaft and is driven by an eccentric so the presence of a skew gear tells you this is an original pump. The original pump bodies are made of mazak which distorts all too easily and as a result, the pump can fail. If you have an original pump, suspect failure, meaning that the pump is not being turned by the engine. An assistant should be able to see if the original pump shaft is turning when you kick the bike over.

Morgo pumps rarely wet sump - never in my experience. Original pumps do.

There isn't an oil pressure gauge on the 53 Square but you can disconnect the oil pipe to the rockers at the T piece and connect an oil gauge there. The rockers will be ok without oil for a short time.

If the sump is full of oil it will escape in any and all directions. So drain it first.

[Bob.Murphy]

There isn't an oil pressure gauge on the 53 Square

EH ! I'm pretty sure mine started life as a '53 Mk I Alloy in Wedgewood blue & white (Coronation Year). It had an oil gauge in the tank. I put a Mk II motor in it, plus a load of modifications that the VMCC 'experts' at the monthly meetings hated.

The original Mk I motor had a Plunger oil Pump, the later Mk II had the Gear Pump.

Was '53 a change-over year to the Mk II ??

Curious.

Bob.