Series II 180 and 120. Do they share any engine parts?

[1200ts]

I have never rebuilt a series II 180 engine. Are the internal parts the same as a 120 or are they the same as an earlier 180? Or are they different than both?

I am mainly interested in the clutch and gearbox parts. Yes I know the crank, cams and ignition are different than a 120.

I have heard of a series II engine near me that blew up and a rod has exited the cases. I have not seen the bike as yet and don't even know where it is so far. I have a120 engine I am working on with really rusty gearbox parts and am hoping the series II 180 parts will fit?

I know the early 180 parts are all different than a 120.

 

[iis_iis]

gearbox cluster, no. Had them side by side 30 years ago, as i recall not the same. Hit and mis the actual compatible parts, again memory, others may be more specific HTH j

edit ** just recalled i had a 180 series 2 crank in series 1 crank cases, configured as a 1981 series 2 engine, indeed there is a story in what i inherited from a previous owner... hope it makes sense...

 

[chrisk]

Copper exhaust gaskets should fit all the above

Sorry, I’m not more help, than that supreme parcel of information

 

[1200ts]

John,

That is not the answer I was looking for. You should have said "yes the parts will fit".

It seems odd that the series II was still being made in 1982 and 1983 at the same time as the 120 and no parts are the same?

I would have thought that when they were designing the series II which was first sold in 1981 that they were already thinking about the 120 which was first sold in 1982? If no parts are the same, poor planning on Laverda's part as it would have saved a lot of money.

Regards,
Bruce

 

[iis_iis]

The many times it has happened my replies or answers met with unexpected result.... "does my bum/butt look big in this dress?" precipice of disaster beckons.... male world translation.. "does my crankshaft fit these cases..?" a man has to decide his fate, right there and then... what say you mob to reply the trap question, the day comes it will be faced, ready or no....

No need to thank me Bruce, harbinger of bad news is a calling few can accommodate... as my memory is poor ( upside is cannot recall my memory being poor, because my memory is poor...) others can dismiss my assertions as to inter-compatibilities.... j.

 

[chrisk]

The many times it has happened my replies or answers met with unexpected result.... "does my bum/butt look big in this dress?" precipice of disaster beckons.... male world translation.. "does my crankshaft fit these cases..?" a man has to decide his fate, right there and then... what say you mob to reply the trap question, the day comes it will be faced, ready or no....

No need to thank me Bruce, harbinger of bad news is a calling few can accommodate... as my memory is poor ( upside is cannot recall my memory being poor, because my memory is poor...) others can dismiss my assertions as to inter-compatibilities.... j.

I’ve had that, does my arse look big in this ….

I reversed the roles once, and said “Your arse looks small in those jeans” only to be struck down, because, “You mean everything else I wear makes it look big?”

Fucked if I know what makes them tick.

 

[Andy]

"Does my bum look big?"
"Do I look stupid...?"

 

[breganzane]

Gearbox and selector mechanism are totally different, also the crank centre main bearings and hence how the crankcases are machined for them. Don't think there's much/anything that is transferable from crank/gearbox/selector. Primary and clutch is the same I think?? Not quite sure when the oil pump grew to 10mm? Alternator, sprag clutch and starter all the same (noting the difference between LH and RH thread alternator rotor bolts). S2 180 gearbox, sprocket cover / selector is the same as a S1.

I don't think it's all that unusual for a small company. They had a comparatively large number of revisions which they brought in progressively throughout S2-180 and 120-Jota (1981 and 82 year models respectively) production, ending up with the fully revised RGS-spec in production by late 82. Having the engines open you can literally see the changes being added. The S2-180 has all the cast-in features for the RGS gearbox selector but they remain un-machined, it being machined to take the earlier setup.

 

[CLEMTOG]

I am have an idea that "SOME" of the gearbox components "MIGHT" fit you could end up with differring ratios, but as Mo says selector etc totally diffferent, the easiest way to check if a component is "IDENTICAL" between the two is to referance the part numbers, for instance the part number for an SF3 swing arm is the same as for a disc braked 180.

CLEM

 

[sfcpiet]

I am have an idea that "SOME" of the gearbox components "MIGHT" fit you could end up with differring ratios, but as Mo says selector etc totally diffferent, the easiest way to check if a component is "IDENTICAL" between the two is to referance the part numbers, for instance the part number for an SF3 swing arm is the same as for a disc braked 180.

CLEM

No. Gearbox internals are completely different, all they share with the earlier stuff is the main- and layshaft bearings and their locations. Shafts, cogs, selector forks and drum are all different, as is the entire selector mechanism.

The 120° gearbox is a huge improvement over the 180°, only really vulnerable point is the needle bearing for the 5th gear exit shaft. This is most often damaged by a too tightly tensioned, totally unforgiving #630 drive chain and usually takes the shaft and gear with it, hence the common conversion to bronze bush. One shouldn't have the impression a #530 chain would any more forgiving though...

piet