New guy with Mk3

[Bevel bob]

I presume you have checked the oil level in the engine, should be close to top of the tube. kicking over with the plug out should bring some oil up. the "Y" branch tube is an oil drain back to the case . If you remove the engine pump cover you are likely to disturb the gears that drive the cam and loose the spark and cam timing ,so not untill you need to!. That looks to be a USA version MK3 , no battery system?. Have you heard it run?, History is very valuable ,do all you can to find out who re-built it and what was done to the engine. Hang onto the Monza till you know all is well. Mine looked like that too !!. Hope your luck is better than mine !!.

[Romomoto]

Thanks, Duccout and Bevel Bob.
Of course! I should have known those were drain-back lines. A senior moment; for decades I've dealt with Nortons and Guzzis, which supply oil to the heads externally and drain back internally. So I jumped to that erroneous conclusion. I know I need a manual so's I can stop asking dumb questions, but I have not found one yet.

As for putting it in gear and pushing it around until it pumps oil, I may have to revert to that option, which I've avoided due to wintery conditions up here in the Rockies right now.

[LaceyDucati]

If the cam has a hole in the end, use an oil can filled with engine oil to pump into the end. That will push oil down the oilways to the pump, you may well find that will help you get oil primed through the system. The oil ways and pump may well have drained/dried out and be struggling to pick up by slow cranking. This may well simply solve your issue and get things flowing.

Regards Nigel

[Romomoto]

Thanks, Nigel. That's just what I was looking for; I just didn't know the oil system plumbing. I bet that will do the trick.

[Romomoto]

Bevel Bob: No, I have not heard it run, and I bought it from someone who has had it a couple decades or more and has not run it in that time. He did not offer me any indication of its mechanical history. I think he bought it as it is now, but younger.

[Bevel bob]

That sounds very much like my story. Even when running reasonably these bikes can be very demanding. Especially those models (M3NC) with big carbs ,racy valve timing and weak ignition systems with advanced and fixed timing. All capped by a restrictive pattern silencer that hints at a performance that it blocks. Why would any sane person ride such a device?. Can't answer that.

[Duccout]

They were modelled on Italian women - temperamental! (am I allowed to say that here?)

[double diamond]

I would agree your Mk3 is a restoration, the Akront alloy rims are not original (although an appropriate enhancement) and the shocks are not original. Something going on with the toolbox knobs too.
Priming the oiling system and freeing the clutch are both good pre-startup procedures. Nigel’s suggestion hadn’t occurred to me but is actually about the simplest method. I usually remove the brass plug on the clutch cover then remove the oil galley plug in the end of the crankshaft. Then you can prime the oil pump with an oil can pump. This will fill the crankshaft as well as priming the top end oil passages. When you re-install the oil drain plug/screen be very careful that you get the end of the plastic screen inserted into the oil pickup in the right side case. Since your Mk3 has been sitting for a long time, I would suggest you lean the bike all the way over on both the left and right sides to get some oil on the various ball bearings inside. The oil sump is separated from the crankcase. the crankshaft and transmission bearings may be dry as they are all lubricated by “splash”.
I have a couple of heads that have a dab of paint on the top. Usually only pretty “young” heads show paint. I’ve speculated that this may have been an indication of the specification of the internals (cam, valves, springs, etc.) as a verification for production line assemblers that they’re installing the correct head for the lower end they’re assembling. This might be assuming a greater measure of production control than actually existed but somehow they got things right? Perhaps if we surveyed owners who have noticed paint spots on their heads, a pattern might be revealed. The heads I’m thinking of are NC scrambler heads with a green dab of paint. Rationally, I would have guessed the paint color would correspond with the color code of the camshaft. Come to think of it, I might have a Diana head with a red paint spot.

Also, what is the engine number? I’d like to see where your example falls in the continuum. Is there a foil tag on the steering head? Might have been removed if the frame was painted. Some tanks have “Tebaldi” stamped on the tunnel viewable from the gas cap.

Matt

[Duccout]

Yes, I always thought that the dab of paint indicated the type of camshaft fitted.

[Romomoto]

Double Diamand (et al): thanks for that. I too thought that the dab of paint might well indicate what cam or other head specs lie within.
And yes, the inside of my tank has a visible label: FLL TEBALDI MONZA.
There is no label on the steering head.
Engine # is DM250M3 100458

When I did the oil change yesterday, the filter/drain plug fit happily into place, so I would think it safe to assume that it nested correctly.

Thanks for the tip re: tipping the bike to left and right to slog oil up into bearings etc.

Cheers