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So, doing a bit of research regarding putting the heads/barrels back on. Do I use any sealing compounds like Hylomar or just the new alloy gaskets on their own ?
I noticed there was red sealant before.

I´m always giving a small amount of Silikon like the red Dirko HT (high temperature) on both sides of the gasket (cylinder bottom and heads).

If you don´t want to take off the blocks of the rocker arms after a few 100 km to retighten the nuts of the head. You can give them a little more torque (perhaps about 2,4 -2,6), leave it alone one day, get the nuts loose again and them give them the right torque (2,1 with a 500 motor if I remember it well). My experience is that I don´t have to retorque again after 500 km as recomended.

I´m not sure, the early 500 motors have already the partly reduced studs for cylinder and heads?

norbert

Thanks Norbert, will look to see if I can find some of that.

Getting bored waiting for the heads to be fixed. Thinking of making a bash plate. Here is a mockup.
Finished painting the motor. Or what I have of it.

I need to think about a bash plate too. I have two plastic Kanguro plates that I was going to adapt but while they are close they just aren't quite right.

I was speaking to the machinist today about using silicon on the head and barrel joints. He warned me not to over use it and block oil going up the head bolt galleries. When I disassembled it there was a lot of red silicon around that area. Do these motors rely on oil being pumped up the head bolts cavities to reach the rockers ? I always thought oil was pushed up the push rod galleries in mist form to reach the rockers.

Any harm if the silicon blocks the head bolt galleries ?

I remember now some of the external head bolt nuts were a bit wet of oil when the motor was running. I think it was from within it was coming from.

Cheers.

Yes you're right about the oil mist supply to the top. Silicon can be used and it should always be used sparingly anyway. The faces on Morini engines are good unless bodged, but even then a tiny amount of sealant will fix most things. Try to get hold of 3M 'Threebond', also known as 'Yamabond'.
It's like silicon but even better. Pricey too but worth it-Reassuringly expensive!

So just to be clear, do they rely on oil going up the head bolt cavity ?

Thanks Steve, as always.

PS,,, I am buying a Ducati head stem for my 71 Scrambler off a Steve Brown in the USA !
Helpful fellas these Steve Browns are

rossguzzi wrote:So just to be clear, do they rely on oil going up the head bolt cavity ?

Thanks Steve, as always.

PS,,, I am buying a Ducati head stem for my 71 Scrambler off a Steve Brown in the USA !
Helpful fellas these Steve Browns are

Ahh, we do our best. About the oil feed, it only (should) go up the pushrod tunnel. Not the barrel studs, they should really be oil free. If oil is getting there you must have something like a bad gasket joint or face. It could also get past the thick washers under the cylinder head nuts but that also means that something there isn't seated right or is damaged/scored etc.
If the crankcase breathing is in order you should be much less likely to have oily incontinence. Ooer missus. So make sure the labyrinth breathers in the rocker boxes are fitted and clean, also at least one labyrinth in the big breather tube on the back of the crankcase. Mind you the Camels originally had the plastic breather bottle instead and that fed back into the airbox. I think the labyrinth is better or a one way valve even better again.

Just got off the phone to a guy in OZ but on the east coast. We were just discussing this issue, as he has had it happen to one of his Morini`s to the extent of it smoking out the exhaust. Silicon around the head bolt on assembly fixed it.
So I may do the same.
I have the plastic catch bottle but the breather tubes that went on the airbox have been cut. They just breath to under the tank leaving a mess. So I wrapped the ends together in a cloth zip tied together. Works ok.

rossguzzi wrote:Just got off the phone to a guy in OZ but on the east coast. We were just discussing this issue, as he has had it happen to one of his Morini`s to the extent of it smoking out the exhaust. Silicon around the head bolt on assembly fixed it.
So I may do the same.
I have the plastic catch bottle but the breather tubes that went on the airbox have been cut. They just breath to under the tank leaving a mess. So I wrapped the ends together in a cloth zip tied together. Works ok.

If oil is getting from the studs into the exhaust surely there must be cracks or damage to a joint face somewhere? If it's getting down the studs that are in the rocker box then it must be the milled faces where the 2mm washers sit (or the washers) that are damaged.
As for the small breather tubes, if they just exit to atmosphere they are missing the vacuum effect of the airbox. That vacuum helps to evacuate crankcase pressure in the same way as a non-return valve would. That all helps to reduce leaks and will also allow the engine to rev more freely. If you cover them with rag or a filter it gets worse! I would get some new tubes either into the top of the airbox or at least poked into the intake trumpet of the airbox. I still think the main breather is best to atmosphere through a labyrinth or a non-return valve (both have the same effect) I'm sure that plastic collector box was only introduced to suit USA emission laws, to recirculate combustion by products etc.

All the Morinis I've owned have had the labyrinths from the crank case and the labyrinths from the rocker boxes venting to air - with no oily emissions.

Ming wrote:All the Morinis I've owned have had the labyrinths from the crank case and the labyrinths from the rocker boxes venting to air - with no oily emissions.

That's how it should be, the labyrinth works as a one way valve. You'll only get oil out of there if something is amiss or the engine is well worn and over worked.

Been a while waiting for my heads and barrels to be done. Got them back and painted them. Still need to get the exhaust thread done. But he is busy till after chrissy. Been to hot for riding anyway. 40 c for days on end !
So here is some pics of the new valve seats. He siamesed the exhaust into the inlet just a bit. Bored barrels, honed, new guides, valves, rings, pistons, the lot.
Bike should outlast me now

Made myself a bash plate while I wait for the head to come back from getting the exhaust thread repared. Came up ok I think