Life after the Slow Monster Rebuild

[350TSS]

My niggling concerns are:
1. for a dry clutch there was oil in the clutch basket, not a lot but if it is supposed to be dry is should be dry. There are two possible sources a) where the clutch push rod exits the input shaft, there is a seal here that is completely bespoke, domed and shaped to fit the gearbox input shaft and because it is bespoke probably unobtainable; and b) between the LH casing and the primary drive gear on one side and the clutch basket on the other. Since I have not stripped this down yet I have no idea whether or not it is a bespoke part but I suspect the since the shaft is c22mm (compared to the pushrod seal at c6mm) this seal is subject to higher speeds and therefore more likely to be the culprit.
2. the green seal at about 7 o'clock on the main crankcase picture above has a substantial indent where it fits into the oil pump in the outer LH casing, I have no idea whether there is is a standard / available replacement.
3. the reason for all this mayhem, the kick starter return spring, is not broken. I am almost certain the casing has never been off since it left the factory in 1976. The symptoms that lead to this were a kick starter lever that would only reluctantly return to its stop position and if the engine was running the lever would droop downwards and the ratchet would start singing. The spring itself is not a flat clock spring but a circular section spring, As such, the possibility of winding it up one more complete rotation to ensure it is positively motivated to return the kick starter lever to the upright position is not really an option as the spring will be coil bound on the kick starter shaft. Anyway, why would the factory not supply the bike with the spring tension properly set, and would not the first owners have insisted that if it had been incorrectly set that it was rectified? There is definitely some slack in the tension of the spring when it is abutted to the retaining post that would lead to the lever dropping off the vertical "home" position.
Over the next few days, I shall
1. research availability of clutch oil tightness seals (pushrod and main input shaft)
2. research availability of clutch cover /oil pump seals
3. design and make a component to ensure sufficient tension in the kick starter return spring such that the lever is sufficiently motivated to return 100% of the time to its "home" position
4. make the replacement clutch spring posts and weld them into the clutch hub

[Luddite]

Is this one of the seals you're concerned about, Richard (no. 60)?





(Mdina Italia again.)
https://www.mdinaitalia.co.uk/M230219.html

They also have a selection of other seals/gaskets, which might be useful.

That slack kickstart spring rings a bell - I think it may have been mentioned in Practical Sportsbikes during one of their restoration episodes but I can't find anything in my back issues. There is a detailed installation procedure in pages 57 & 58 of that manual I linked you to so have a look there before trying to modify it.

[350TSS]

Luddite: thanks once again - when I read your previous advice, in my enthusiasm to get the copied pages, I missed the download link for the manual which, as I write, is printing off.

[Darren69]

I'm sure there was something in Practical Sportsbike a few months back about setting the correct load on those unusual clutch button things.

[350TSS]

Yesterday I was stwuggling. The kick-starter mechanism was the culprit.
Long in the distant past with my old British bikes (and even my current MZ) the kick-starter mechanism was a geared quadrant that engaged with the gearbox main shaft when the lever moved off its stop. When the engine eventually fired a ratchet engaged and stopped the engine driving the kick starter lever round in circles. When the quadrant was disengaged, when the lever was on the stop, there were no moving parts and the clock spring (pre-tensioned on fitting) held the lever on the stop. Simple but effective - each component had one job and each was stationary when disengaged.
The problem I have with the Morini is a kick-starter that does not return to its stop after use, rather it droops under the weight of the lever and secondly the ratchet is obviously engaging even with the lever on its stop.
Here is a picture of the arrangement:

The components working towards the centre-line of the engine are the lever itself, the shaft, an O ring, an outer spring collar, the coil spring with two tangs, one of which goes through the outer end of the shaft and obviously tensions the spring when the lever is operated, and the other tang (the fixed end) which engages on a post which slides into a hole in the main crankcase. Next,after another sheet metal spring retaining collar, there is a heavy component that is splined onto the shaft and has ratchet ramps machined on the inner ward face These ramps engage with ratchet ramps on the outer face of the kick starter gear itself. This meshes with a corresponding gear on the mainshaft. This kick-starter gear, I think, spins on the kick-starter shaft all the time the engine is running.
As far as I can work out the spring in the Morini design performs two functions, as soon as the lever is moved off the stop the tension increases encouraging the lever back to the stop, the second function, I think, is to manoeuvre the splined ratcheted component into engagement with the ratchet on the outer face of the kick-starter gear.
I must have had the assembly together with the outer case on and off about 5 times yesterday. You need to put the case on in order to set the pre-tension on the spring. I set it exactly as per the manual and the lever drooped and the ratchet was still engaged, I tried it with varying increasing levels of pre-tension on the spring and whilst the lever rather lazily returned the ratchet was solidly engaged.
After a couple of hours and before I took a club hammer to it, I walked away.
Writing this down has helped me work out what I think is wrong.
1. As the ratchet is always engaged to a greater or lesser extent, the kick starter gear is c 3mm too far away from the centre-line of the engine. It is snagging on a wear mark on the shaft and cannot cam out of the ratchet sufficiently?
2. The fixed end of the coil spring necessarily must move along the post when the kick starter lever is activated. There is the possibility that this fixed end of the spring is snagged and cannot move back thereby keeping the ratchet engaged?
Guess what I will be doing today?
PS The manual I downloaded is for a later year Morini and shows a drawing of the set up of the spring. The fixed tang of the spring in the drawing is the opposite way round to the spring I have inside my gearbox????

[350TSS]

A rather successful day today, the kick-starter is back in place, the lever returns to vertical, perhaps a little lazily but does so and there is no ratcheting noise when I turn the clutch/gearbox input shaft.
I stripped it down again and found a slight witness mark on the kick-starter shaft where the gear runs this was I think causing the ratchet to be constantly engaged as it restricted the movement of the gear towards the centre of the engine.
Also, the return spring had a burr on it where it contacted the retaining post.
With both of these very minor imperfections remedied I put it back together, which was a lot more difficult now that everything moved as it should, holding the whole assembly in the correct position, engaging the shaft in the crankcase and meshing the gear whilst retaining the pre-load on the spring and inserting the spring retaining post. The clutch cover then had to be manipulated so the gearbox shaft came through the clutch basket, the oil pump seal located in the boss in the outside case and the ignition trigger shaft lined up with the oil seal in the outer case, all whilst maintaing a compression on the spring otherwise the component of the assembly just went their separate ways
I did manage to tear the outer half of the gasket where it went around the outside of a case retaing bolt but the inner portion is intact so cross fingers it will still seal.
The remainder of my time today was machining M10 bolts to make replacement clutch spring posts. Making 5 posts exactly the same stretched my measuring and machining skills and I was very glad I bought a 4.2 mm drill to tap out 5 posts each for 22mm. Tapping aluminium I can usually get away with a 4mm drill but a high tensile bolt is a different kettle of fish. These should get welded in tomorrow and the clutch can then be re-assembled.

[350TSS]

A little more progress, the modified bolts are now clutch retaining spring posts and are welded into the back of the clutch hub.
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I also found out why the clutch had a bit too much oil in it. There is a seal on the end of the main shaft through which the clutch push rod operates. The end of the pushrod looks like an exhaust valve from a small capacity 4 stroke; the pushrod is about 5mm dia with the head that operated the pressure plate about 15mm diameter. The shaft had some scoring where the seal ran so I thought I would clean that up with some 600 wet and dry. I put it in the drill and the head was running out about 1mm so the pushrod shaft is bent. In the vice, I reduced the runout but could not eliminate it.
The rest of the time today I spent making rubber grommets for the cable routes through the cases from the electronic ignition and the alternator and looking for the flywheel puller tool that I have put in a safe place somewhere.

[350TSS]

After tripping over boxes of Morini parts about 3 times this morning I decided that it was time to start serious reassembly. A bike in bits takes up at least 5 times as much room as one not in bits.
I had intended to take the heads off to check the bores whilst the engine was in the stand but I can do that with the engine in the frame or....... when I get it running if it does not smoke I might just leave well alone.
I do need to change the cambelt but that is just as easy in the frame.
The frame was wrapped in old tee shirts and taped up so they could not get displaced and within 20 minutes the lump was back in its rightful place. The engine itself is not that heavy, at a guess, less than 40 kilos. If it was more I do not think I could have maneuvered it into place.
Because it is more than 40 years old I do not need an MOT so if I hit any wiring problems with lights or indicators I can still ride it during daylight hours without the need to get it perfect.
State of play at 15.00 today.
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[Luddite]

That must have been very satisfying, Richard. I've always thought that the Morini engine is one of the nicest looking air-cooled lumps around - something to do with the shape of the crankcases and the clean-looking cylinder heads.

Really looking forward to seeing the finished product. Keep up the good work!

[Dave G]

Getting access to remove the cambelt was a real pain in the backside I do remember ( I have a puller if you cant find yours), I cant actually recall which of the nuts was the really difficult one to loosen but what I would recommend is not faffing around with ways to lock the cams etc and just use a rattle gun, it took me a few days of trying before I bought an electric impact driver just for this job and it took seconds, didnt even need to lock anything from turning.

[350TSS]

Thanks Dave G, I found my puller and with the aid of a rattle gun the flywheel/alternator rotor was soon off.
The alternator is inside out, the windings are held onto the crankcase by 3 x 6mm set screws and the magnets are attached to the inside of an aluminium flywheel that is on a taper with a very shallow woodruff key. It will not be possible to centralise the air gap between the rotor magnets and the windings because the aluminium flywheel housing is in the way.
The right-hand outer casing has similar slots cast into the front but unlike the clutch side these are not blind so the flywheel and windings and the end of the crankshaft are effectively exposed to the elements.
Inboard of the flywheel there is a coil spring that had corroded solid to the crankshaft. A couple of doses of penetrating oil and a large lever freed it off. Inboard of that is a circlip, a lighter gauge coil spring and the dished outer belt retaining plate. The dishing is obviously designed to encourage the belt to stay on the pulley as is the spring loading of the plate.
There is no means of belt adjustment consequently belts are made in 3 sizes (A, B and C). Replacement is scheduled at 20000km or 3 years or if the trailing run of the belt can be moved more than 6mm at the centre point between the two pulleys. Belts are c £37 each delivered within a couple of days.
The belt drives the camshaft between the V and at the other end the electronic ignition trigger.
Because it runs at half speed there is obviously no wasted spark on the ignition system.

[350TSS]

Today was mostly spent changing the cam belt and messing with the petrol taps.
The old cambelt was very reluctant to move off the pulleys. For some reason, I did not want to cut it off in case the camshaft moved and I lost the timing position. As a precaution, I dabbed some paint (I could not find a small brush so it was quite a lot of paint) on the timing marks and noted that the starting position for the crankshaft mark seemed to be about half a tooth out.
With such a short belt and no adjustment on the trailing run of the belt, I reasoned that it had been built that way as there was no way it could have been otherwise.
Eventually, the old belt tore and it was off. There had been about 8mm slack in that old belt. The new belt at first appeared too short and I contemplated taking the camshaft pulley off but I did not have a puller that was capable of getting behind the pulley. The two holes in the face are not threaded so I could not easily fabricate one. After a bit of a struggle and the application of some rubber grease the new one was on in the exact same position as the old. The slack on the belt on the trailing run is about 4 mm.
taking care of betta fish
There are two petrol taps on the Morini, a reserve tap which is a normal lever tap and the main tap which has an electric solenoid that opens it when the ignition is switched on. Both were completely blocked with crud from the old tank. I removed the solenoid part and put both taps in the ultrasonic bath for about an hour. The reserve tap became usable but the solenoid tap has a stepped internal routing which means blockages cannot be removed with a drill bit or electrical screwdriver. Also, when I tested the solenoid bit it showed no signs of life, so it looks as though I shall have to source a new solenoid tap (or a suitable non solenoid tap).

[350TSS]

Only had a couple of hours today. The original Regina chain was completely mullered although the sprockets are barely worn. I normally change chains and sprockets together as a new chain will wear faster on old sprockets (and vice versa) but the sprockets seem to be temporarily unavailable in the original sizes and for potential conversion to 520 chain only the rear sprocket was available. So I ordered 525 x 98 link DID chain off ebay.
It arrived this morning but:

it did not fit. WTF!!!
What was Mr. Moroni thinking? The sprockets appear to be 530, the poor little engine with 30 something bhp could barely drag that around. Needless to say, a 530 chain is now on order but it will have to be shortened as it was designed for a Honda Blackbird.
The remainder of today was soldering small gauge wires to the 3 indicator lights on the dashboard. Some while ago in a bit of a drunken haze bought this little device from Banggood or Aliexpress for less than a tenner. Worth every penny when trying to do fiddly little soldering jobs. Tomorrow if I get round to it I shall drill and tap the base and mount it on a 100mm x 100mm x 10mm aluminium base to give it a bit more stability.

[350TSS]

A bit more progress over the last few days, I made up the 530 rear chain and managed to get the plate spacing within 0.05mm of the rest of the chain and the rivet heads compressed to within 0.07 of the rivet heads on the rest of the chain. My chain maker/breaker is a bit laborious as past experience has taught me; you compress the plates a bit then measure it, do it up a tad more and it is still too wide, and then all too easily you have gone too far and the chain has a tight link. You have to creep up on it slowly and methodically which is what I did in this case. Result.
I managed to source two petrol taps from a Bevel twin (£40) as the correct Morini taps including one with a solenoid were simply not available. It is an odd way of doing it there is a male boss threaded M16 x 1 welded to the tank base and the tap has a nut about 12mm deep, the tap itself has a left-hand thread and between the end of the tank boss and the tap there is one of those tubular plastic filter screens so the nut is only c 6mm onto the tank boss and the tap is only < 6mm onto the nut compressing the screen.
I did a bit of wiring tidying up but soon got bored with that so thought I would give the carburetors one last clean and re-assemble them (I cannot put them together completely as I am awaiting delivery of the pilot jet). Clumsily I managed to drop one of them and broke the lever that controls the choke on that carburetor. The lever lifts a 4mm dia brass rod attached to a piston with a seal at the bottom. The piston is normally held down by a spring and the lever is attached to the brass rodd by a 2mm brass pin. The brass rod passes through a small casting that is secured to the main body of the carburetor by a 5mm countersunk screw.
I made a new lever out of some 10mm plate, drilling 4mm holes in two planes to form a slot to take the brass rod. A lot of filing was involved and it took some time but did not cost anything to replace a part that probably is not available anymore.

The replacement is not as elegant (or fragile) as the original but it was quite satisfying getting it made and it works as it should.

[Luddite]

Originally Posted by 350TSS

I managed to source two petrol taps from a Bevel twin (£40) as the correct Morini taps including one with a solenoid were simply not available.

Is it one of these - part no. 34.02.06? (Much more expensive than your solution - and from Germany - but if you're after authenticity...?)

https://www.motomorinideutschland.co...i-ersatzteile/